Merge pull request #16 from cnoon/master

Fixed compiler error on Xcode 6.1 for NilLiteralConvertible protocol conformance.
Added more layout attributes
Merge branch 'master' of github.com:Masonry/Snappy
Fix issues when using edge insets in an equalTo

The right/bottom edge needed to be inverted to apply a propery "EdgeInsets" rather than "EdgeOffsets" behavior.
Fix snp_makeConstraints clobering existing constraints
Add platform check for additional constraints attributes.
grammar.
Code Snippets!
Delete Snappy Constraint Update code snippet, 'cos snp_updateConstraints don't exist.
Merge pull request #31 from ryanmaxwell/master

Code snippets
Merge pull request #24 from schwers/fix_make_constraints

Fix snp_makeConstraints clobering existing constraints
Merge pull request #28 from devxoul/patch-1

Add platform check for additional constraints attributes.