implement inventions list window, fixes #630
fix compile error for GCC
add manage track design window (UNTESTED)
Fix a bug in sub_6E7F34 and reenable new code
Condition fix in viewport.c
fix various footpath bugs and refactor, fixes #637
Fix viewport tearing.
implement more footpath construction and window
Properly pass dx and bp
Merge pull request #1 from duncanspumpkin/viewport

Fix viewport tearing issue
Remove a no longer relevant comment
Merge pull request #641 from adrian17/viewport_fix

Fix for sub_6E7F34 in viewport.c
s/spekhastighet/spelhastighet/
s/acceleras/accelereras
s/tranporterar/transporterar
s/Gånvägen/Gångvägen
Separate external libraries and language files into VS projects
Merge pull request #645 from mharrys/spellfix-swedish

Update swedish.txt
Added construct dropdown function fixes #638.
Merge pull request #647 from duncanspumpkin/fix_ride_construct

Added construct dropdown function fixes #638.