Basic analysis of window_map_mousedown

* This function doesn't appear to relevant for the normal map window, as
it doesn't have the required widgets. Considering that the Scenario
Editor has a more complex map window, I assume that this function does
processing referred to that instance instead.
start implementing window_track_place
implement window_track_place_toolupdate
add zoom touch gesture support
Merge branch 'master' of https://github.com/IntelOrca/OpenRCT2
palette effects
Merge branch 'master' into track-list-window
fix path bug and implement tooldown for place track
Merge pull request #484 from marcotc/work

Basic analysis of window_map_mousedown
refactor window_track_place.c
small fixes

palette effects

small fixes

palette effects

small fixes

Merge branch 'test'

Conflicts:
	src/window_music_credits.c

palette effects

palette effects

small fixes

Merge branch 'test'

Conflicts:
	src/window_music_credits.c

palette effects

small fixes

Merge branch 'test'

Conflicts:
	src/window_music_credits.c

Merge branch 'master' of https://github.com/zsilencer/OpenRCT2

Merge branch 'master' of https://github.com/zsilencer/OpenRCT2

Merge branch 'master' of https://github.com/zsilencer/OpenRCT2

Merge branch 'master' of https://github.com/zsilencer/OpenRCT2

Merge branch 'master' of https://github.com/zsilencer/OpenRCT2

Merge branch 'master' of https://github.com/zsilencer/OpenRCT2

Merge branch 'master' of https://github.com/zsilencer/OpenRCT2

Merge branch 'master' of https://github.com/zsilencer/OpenRCT2

added window_music_credits.c

added window_music_credits.c

Merge branch 'master' of https://github.com/zsilencer/OpenRCT2
implement window_track_place_draw_mini_preview
Merge pull request #501 from zsilencer/master

0x006838BD, 0x006BA8E0
Merge branch 'track-list-window'