Add category method to print constraint as equation
Prevent accidental constraint decl with =

Accidentally defining a constraint using = instead of == would result in the constraint not being added -- without any warning.  I've defined AutoLayoutDSL::View::operator=() private so the compiler will catch it.
Add UIView category method to log ambiguities
Fix -[NSLayoutConstraint remove]

Add tests for remove
Update pods and project file
Merge branch 'feature/various_improvements' into develop
Add KeyboardProxyView and build example
Clean up NSLayoutConstraint equationString
add allConstraints category method
Fix warnings - especially on 64 bit builds
Add HH prefix to KeyboardProxyView
Prepare for pod update
Merge branch 'feature/add_keyboard_layout_proxy_view' into develop
Bump version (0.2) and build (1). Update changelog.
Merge branch 'release/0.2.0'