Added RACSignal constructors for zero values
Update the ResizingWindow demo
Style fixes
Merge pull request #43 from github/zero

Added RACSignal constructors for zero values
Merge branch 'master' into easier-signal-naming

Conflicts:
	ReactiveCocoaLayout/RACSignal+RCLGeometryAdditions.m
Merge branch 'easier-signal-naming' into negation