Add PHP 5.6 to travis
Merge pull request #23 from RSully/pr_php56

Add PHP 5.6 to travis
Merge branch 'master' of https://goetas@github.com/goetas/xsd2php.git
Interface inheritance
Undefined types
global schemas
New generation and serialization model
Install xmldiff
xdebug max nesting
zend code gen missing dep
Optimized tests
Merge remote-tracking branch 'origin/generator'