Add proxy property to Compound and Property
Move apply to LayoutProxy
Move == to Property
Add Equality and Inequality protocols
Extract + and - into Addition protocol
Extract * and / into Multiplication protocol
Move apply to LayoutProxy
Add Context
Add replaceConstraints function
Change asserts to work with CGFloat
Move car_updateAutoLayoutConstraints into the context
Make LayoutProxy.context & .view internal
Rename car_updateAutoLayoutConstraints
Remove constrain replacement
Fix addConstraint to not trigger layout
Rename to constrain
Use constrain in specs where appropriate
Merge branch 'master' into refactor

Conflicts:
	CartographyTests/DimensionTests.swift
	CartographyTests/EdgeTests.swift
	CartographyTests/OperatorTests.swift
Make Edge conform to Multiplication
Merge pull request #29 from robb/refactor

Refactoring, add Constrain function