Fixes #936

Found via `codepell` (v1.17.0.dev0)  
```
codespell -q 3 -L iff,iif,inport,sord,sinc,te,uint -S ./source/includes,./source/modules,./source/native-plugins,./data/windows
```

When activated, fixes noise and lefovers in background canvas area

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

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

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

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

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

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

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

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

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

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

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

Fixes #850
Fixes #838

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

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

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

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

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

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

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

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

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>

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.