add -DGEM_INTERNAL to all internal modules

rather than using @GEM_CPPFLAGS@ for this
remove -DGEM_INTERNAL from GEM_CPPFLAGS

it's now added explicitely
backup the ATL-based filmDS

we want to get rid of this, but first we need to make an alternative work.
include filmDSATL in the autotools project
switch to new (old) filmDSatl

for now, once the new code is working, we switch back
Don't include QuickTime-headers

QT initialiasation is now done in the resp. plugins
Fixed reverse flags

somehow we added _LIBS to CXXFLAGS and _CFLAGS to LIBADD...
removed construction of MAKEDEP_FLAGS

this is automagically handled by autotools
check whether we have assimp2 or assimp3

and have two automake conditionals HAVE_ASSIMP2 and HAVE_ASSIMP3
only build modelASSIMP2 if we have libassimp2

and not libassimp3!

Closes https://github.com/umlaeute/Gem/issues/77
Merge remote-tracking branch 'avilleret/model_plugin'
move VertexBuffer into Gem/

only objectclass implementations should live in Geos/
finalize relocation of VertexBuffer to Gem/
remove #ifdef checks for building modelASSIMP2

we only build this module, if we have assimp2,
so no need to double-check
return compile status after rebuild on render()
initialize m_refresh member variable
first working modelASSIMP3 plugin
avoid crash when drawing empty arrays
pass model data to VBO

also add a m_refresh bool to update VBO arrays
pass model data to VBO