fix crash of scenery window when selecting the first entry of a given type
Merge pull request #411 from qcz/scenery-crash-fix

Fix scenery window crash
Change staff hire button text, as discussed
Change string to reflect earlier discussion
Initial work on music credits.
Finished decompiling window_music_credits.
Fixed padding for widgets.
Changed place on WC_MUSIC_CREDITS and WC_PUBLISHER_CREDITS.
Merge pull request #413 from Gymnasiast/patch-1

Complete Dutch translation with new staff hire button text
Merge pull request #415 from hexdec/window_credits

Window music credits
Added minimap window resizing

- Identified some unknown methods and fields - process_mouse_tool,
bufsize
- Added map window events and methods - window_map_tooltip,
window_map_set_bounds
Merge pull request #416 from KingHual/master

Added minimap window resizing
Added rough widget_state_pressed function
Started adding dropdown control
Finished dropdown part.
Fix mistake with dropdown window. Still a mistake in dropdown code
Fixed dropdown bug. Added mouse up code.
Added state==5 code
Fixed dropdown issues need to add error handler
Added new function to window_dropdown. Cleaned up input code