fixes #91

the source of the issue was the difference of file structure between normal and library use
some typo fix here
snapshot
renaming hierarchical dropdown to hierarchical menu
working finally
few new meta and type related functions to core
constraint serialization now added
another constraint related bugfix
removed unnecessary file
Merge branch 'master' of https://github.com/webgme/webgme into snap
Merge branch 'addon' of https://github.com/webgme/webgme into snap
hotfix for [#95]
Merge branch 'master' of https://github.com/webgme/webgme into snap