more Makefile stuff
Merge branch 'master' of github_daftfad:TheDarklingWolf/Cataclysm-DDA
[bug] Allow building of later stages of constructions even if first
condition not satisifed.

Fixed makefile yet again.
Fixed incorrect math for construction hotkey 'i'.

Construction staging ACTUALLY  fixed this time.
Merge pull request #17 from daftfad/master

construction bugfixes and more build changes