Add editable (!readOnly) and enabled (!disabled) methods to navigator to make tests easier to read.
Merge branch 'master' of https://github.com/geb/geb
Check which elements the disabled/enabled/readOnly/editable assertions are being made upon and throw an exception if they are not of a suitable type.
Merge branch 'master' of git://github.com/aiten/geb

Conflicts:
	module/geb-core/src/test/groovy/geb/navigator/NavigatorSpec.groovy
Whitespace
isEnabled() and isEditable()