Closes #773

Signed-off-by: falkTX <falktx@gmail.com>

Signed-off-by: falkTX <falktx@gmail.com>

Signed-off-by: falkTX <falktx@gmail.com>

Signed-off-by: falkTX <falktx@gmail.com>

Signed-off-by: falkTX <falktx@gmail.com>

Signed-off-by: falkTX <falktx@gmail.com>

Signed-off-by: falkTX <falktx@gmail.com>

* patchcanvas: Working Ctrl for rubberband selection

* patchcanvas: optimize calls in zoom-fit

* patchcanvas: optimize fixScaleFactors

* patchcanvas: speedup zoom_in/zoom_out

* patchcanvas: disconnect ports by Ctrl+MidButton

* patchcanvas: optimize rubberband update

* patchcanvas: correct cursor unset

* fixScaleFactor: support transform argument

* patchcanvas: speedup wheelEvent handler

Direct operations on QTransform go faster than via QGraphicsView
convenience methods.

* patchcanvas: optimize QPointF construction

* patchcanvas: Сursor for connection cut mode

* patchcanvas: rubberband scaling support

* patchcanvas: Limit top scale by canvas size

* patchcanvas: Fix box position after each movement, even creation

* minimap: Scaling support

Pressing RMB after LMB activates special scaling mode. Scroll wheel to
scale in any mode or without such.

* patchcanvas: Take port lineHinting from chosen pen

* patchcanvas: Set default port offset to 0px

Besides of more tidy look with certain themes, it also noticed to be
workaround for problem, when connection lines get under port's parent
box, after selection changes.

* patchcanvas: Finer connection placement relative to ports

Squashed commit of the following:

commit 0449cd63f7
Author: Nikita Zlobin <nick87720z@gmail.com>
Date:   Fri Oct 5 02:19:23 2018 +0500

    carla skin: fancy item selection

commit 84a7b527a7
Author: Nikita Zlobin <nick87720z@gmail.com>
Date:   Fri Oct 5 02:10:49 2018 +0500

    carla skin: drawOutline: fixed positioning and optimization

commit 30681d1523
Author: Nikita Zlobin <nick87720z@gmail.com>
Date:   Fri Oct 5 01:20:53 2018 +0500

    carla skin: drawOutline: set brush only once

commit 63d2ab2e21
Author: Nikita Zlobin <nick87720z@gmail.com>
Date:   Thu Oct 4 00:10:39 2018 +0500

    carla skin: more neat QColor to tuple conversion

commit 2137b78109
Author: Nikita Zlobin <nick87720z@gmail.com>
Date:   Wed Oct 3 16:35:48 2018 +0500

    rack item: Skin-independent colorization support

    Color menu item tints background color, preserving all visible
    relief. No need to lock it for some skins.

commit 13fa4f2c34
Author: Nikita Zlobin <nick87720z@gmail.com>
Date:   Wed Oct 10 15:00:58 2018 +0500

    rack list: Colorized padding

commit 9964af1994
Author: Nikita Zlobin <nick87720z@gmail.com>
Date:   Fri Sep 28 17:48:17 2018 +0500

    rack list: Colorized rails

commit d212577057
Author: Nikita Zlobin <nick87720z@gmail.com>
Date:   Wed Oct 10 14:12:36 2018 +0500

    rack list: Set frame in ui form

commit 9a7e060988
Author: Nikita Zlobin <nick87720z@gmail.com>
Date:   Fri Sep 28 18:44:49 2018 +0500

    rack list: Set common frame

* minimap: Update on any selection change

For now minimap is already updated when box (not port) is selected.
Also it will update if port is selected by Ctrl+C while box is already
selected. This commit just makes this behavior more stable and
predictable,

* minimap: Align frame bottom with canvas frame

* minimap: Fixed & unified cursor pos expressions

Another approach, yet working in both places without rewriting.
Don't add xp or yp, as it displaces right/bottom limit by 1px

* minimap: Better custom frame

New implementation has outer 1px shadow above parent background
and internal enlight border above background. All is pixel-aligned.

* minimap: Fix cursor position on lowest scale

When scale is close to 0.2, view area may become bigger than working
area. After such "fix" viewRect position is broken.

* minimap: Brightness-aware shading on side gaps

* mininap: Set viewRect lineHinting from proper pen

* minimap: Cliped rendering for rounded corners

* minimap: Frame width awareness

Draw content only inside frame when external qt theme is used.

* minimap: Implement full resize with any ratio

* minimap: Better cursor positioning

* minimap: Minimal corner rounding

Make rounding to look good with rounded frames, still not ugly
with square themes.

* minimap: Reworked frame

Mimic tab frame by placing existing frame as line child to QTabWidget.
Frame derivation still handy to create inner sunken frame, just like
in two other frames around.

* minimap-framewidth: Follow system style change

* minimap: Special blending modes for view cursor

Adding for dark color schemes and subtracting for light preserve more
contrast, compared to default blending. Difference is calculated from
background and rubberband colors.

* Better buttons look in sidebar fileview

* minimap: Hold cursor inside map in view move mode

* minimap: Natural move

Would be more natural to have centered position in canvas view, when
pointed in minimap.

* Add confirmation dialog for quitting Carla

* Make exit confirmation dialog configurable

* Don't save confirmExit in the host object

* Don't set host.confirmExit in loadHostSettings either

* Modify .ui file using qt4 designer

* Change config ui back to original size

* Put check for exit prompt on multiple lines

* Convert (not ==) to (!=)

one typo

Consistency (the GUI button to be pushed is named "Scan", not "Start").

Closes #546

Thanks to Jan Ypma for some base code
Closes #332
Closes #374