Updated ObjLoader with group loading functionality.
Added range check to group index
Added check to see if new index is different from old before reloading.
Changed constructors.
Removed unused init function.
Load before returning getNumVertices, getNumIndices, getAvailableAttribs.
Updated usage description.
Added clearing of indices when loading.
Updated includes.
Changed loadNormals, loadTexCoords to includeNormals, includeTexCoords to resemble ObjWrite.
Merge branch 'glNext_vboRework_ObjLoader' of github.com:thyrrestrup/Cinder into thyrrestrup-glNext_vboRework_ObjLoader
TriMesh::recalculateNormals() setting mNormalsDims correctly
Minor formatting updates
Updates to ObjLoader sample