implement window_dropdown_show_colour
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.
Fixes #482 caused by not passing the widgetIndex and x and y coordinates.
Added some checks on object loading to eventualy fix #225
Merge pull request #486 from duncanspumpkin/fix_482

Fix #482
Decompiled published credits window.

Renamed window_credits to window_music_credits.
Added draw_string_centred_underline to gfx.c.
Merge pull request #489 from hexdec/window_publisher_credits

Decompiled publisher credits window.
start implementation of track list window
implement scrollmouseover and scrollpaint for track list window
implement track list window paint
implement window_track_list_select
implement track_get_info
implement sub_67726A, track loading function
Merge branch 'track-list-window'
start implementing window_track_place
Add symbolic link if it is not present
Merge pull request #495 from kevinburke/symbolic-link

Add symbolic link if it is not present
Update readme.md

Hope this small change will give the project more attention by adding a link to the OpenRCT2.com precompiled builds.
Merge pull request #497 from JarnoVgr/master

Update readme.md
implement window_track_place_toolupdate