filling in the gaps from LJS 2.0

* added isFuture and isPast to NSDate category
* added some helper functions for LjsIntegerInterval
fixing up some compiler warnings around signedness
turned on modules, converted to NSTextAlign... and NSLineBreakBy..., addressed some xcode 5 analysis problems
updated the progressive migration to ignore model pairs where the source is older than the target
added index path category
added s_nth to array category to allow signed integers to be passed to nth
added some ios version handling defs
first in a series of very complicated edits to make compat with 5 - 7 iOS
the next step on the quest to handle iOS 7 and iphone 5
Merge pull request #2 from LittleJoySoftware/riseup-branch

riseup has enough iOS 7 vs. the world stuff in it to be useful to the other project branches