implement research_update
implement research_calculate_expected_date
implement research_update_uncompleted_types and refactor research
fix #506 Paths can no longer be placed
vehicle sounds now using Mixer

Fixed bug that caused widgets to miss draw. Fix #335

Merge pull request #505 from duncanspumpkin/gfx_rect

Fixed bug that caused widgets to miss draw.

fix #506 Paths can no longer be placed

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

vehicle sounds now using Mixer

Fixed bug that caused widgets to miss draw. Fix #335

Merge pull request #505 from duncanspumpkin/gfx_rect

Fixed bug that caused widgets to miss draw.

fix #506 Paths can no longer be placed

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

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

Fixed bug that caused widgets to miss draw. Fix #335

Merge pull request #505 from duncanspumpkin/gfx_rect

Fixed bug that caused widgets to miss draw.

fix #506 Paths can no longer be placed

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

vehicle sounds now using Mixer

Fixed bug that caused widgets to miss draw. Fix #335

Merge pull request #505 from duncanspumpkin/gfx_rect

Fixed bug that caused widgets to miss draw.

fix #506 Paths can no longer be placed

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

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

vehicle sounds now using Mixer

Fixed bug that caused widgets to miss draw. Fix #335

Merge pull request #505 from duncanspumpkin/gfx_rect

Fixed bug that caused widgets to miss draw.

fix #506 Paths can no longer be placed

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

Merge branch 'master' of https://github.com/zsilencer/OpenRCT2
Merge pull request #507 from zsilencer/master

vehicle sounds now using Mixer
Merge branch 'research-update'
Merge branch 'master' of https://github.com/IntelOrca/OpenRCT2
Merge branch 'master' into reorganise-src

Conflicts:
	projects/openrct2.vcxproj
	projects/openrct2.vcxproj.filters
	src/audio/audio.c
	src/audio/mixer.h
	src/game.c
	src/ride/vehicle.c
	src/windows/finances.c
	src/windows/research.c