Add initial hotkey support in glinject

Hook onto XNextEvent and communicate back to the main application. Also
support very initial and primitve resolution at the main application
side.
Improve signalling, add hotkey_enable

Use a running counter to signal and detect changes. Add a hotkey enable.
Pass keycode, not keysym to glinject

This avoids the unneccessary call inside glinject.
Inline simpler functions
Inline GetHotkeyModifiers

Functions it uses are inline already...
Add a 100ms timer for polling glinject
Merge branch 'master' of https://github.com/borancar/ssr.git

Conflicts:
	src/GUI/PageRecord.cpp
	src/GUI/PageRecord.h