Some hosts check the VST-standard version of plugins.
This fixes MIDI Ports, which are only available in VST 2.x, for some hosts (Ardour 5.x in particular)

(thanks, Cameron!)

Run lglw_events in effEditIdle (debug plugin)
Run lglw_events in effEditIdle (VSR plugin)
Run effEditIdle loop in debug host if no _XEventProc
Temporarily swap lglw_log for printf (needs fixing)
Suppress most mouse event messages
Bring back sending of child events to parent (rare occurence)
Cleanup some lglw_window_open code
lglw_window_open event mask setup to receive events for itself
Comment the setting of _XEventProc (to get to effEditIdle loop)
NoEventMask on mouse grabbing, possible fix for grabbing issues
Setup working and non-blocking lglw_events

vst2_lglw_debug_plugin extracted, makefile made
vst2_debug_host temporarily using this debug plugin
vst2_debug_host Linux support for XWindows, _XEventProc
Temporary logger change to avoid crashes (needs investigating)

LGLW for Linux:
Include necessary X and GL headers
Temporary static log file and XErrorHandler for debugging
Many logging statements
loc_create_hidden_window implemented and working
loc_destroy_hidden_window implemented and working
lglw_window_open implemented and working
lglw_window_resize implemented and untested
lglw_window_close implemented and working
lglw_window_show implemented and untested
lglw_window_hide implemented and untested
lglw_window_is_visible is implemented and untested
lglw_window_size_get is implemented and untested
lglw_redraw is implemented, but possible wrongly
lglw_glcontext_push implemented and working
lglw_glcontext_pop implemented and working
lglw_swap_buffers implemented and working
lglw_swap_interval_set implemented and untested