render_label() and render_field() no longer require TT

Include render_label() in tests
remove 'nested_name' method from SingleValueField role - duplicated Field role
moved as() method into Coercible role
fix test file when running under 'tt' render_method
remove unused TT file
'string' render-method changed to use new layout() for all fields
handle deprecation on reverse_single and reverse_multi. docs
TT render-method passing all tests
render_label() and render_field() no longer require TT

Include render_label() in tests
Merge branch 'layout'
change remaining uses of 'base' to 'extends'
update docs to use 'extends' instead of 'base'
Bundle our own (renamed) copy of MooseX::Attribute::Chained to avoid warnings under perl 5.19.x
don't require/use MooseX::SetOnce - it's not used
remove unused prerequisites
update Changes file
update Changes and version no. for cpan release