Couple of defines for building against PRMan17.
Adding ability to store tags in scene locations with links to external files (LInkedScene).
These tags will, at reading time, be returned to all the child locations as if the linked scene had that tag on all levels.
Merge pull request #15 from ldmoser/tagsAtLinks

LinkedScene: adding ability to store tags in scene locations with links
Merge pull request #13 from danbethell/prmanBuildFix

Couple of defines for building against PRMan17.
fixing test so it can be run standalone
Making listToSceneInterfaceNameList public so we can use it in IECoreMaya bindings
Tidying up the Houdini custom tag code before porting over to Maya
Changed customTagReader registration to match IECoreHoudini.

Custom tag readers now register both has and read functions, and are no longer registered on tag name. They instead allow any dapPath to have or read any tag, and all custom tag readers will be called during readTags.
SceneShape registers a custom tag reader with MayaScene.

This simply translates the tags already existing in the scene file, and does not currently allow for live editing/addition of tags.
adjusting test for python tag registration so it doesn't interfear with the SceneShape test
Merge pull request #20 from andrewkaufman/mayaSceneTags

Maya Custom Scene Tags
Merge branch 'master' into coreGLMac