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The shared and weak pointers are now included via ACGL.hh, this way there is one
one central place to replace the pointers if needed (C++11, TR1, boost, own variant).
For this, they are placed in a ptr namespace so std:: (C++11) and str::tr1:: (C++98)
variants as well as boost and own implementations can all get redirected.
C++11 detection added and correct non-tr1 header include added (should make VS2010
porting easier).

* Furthermore introduced a factory to register new file types (currently jpg and png).
* Added support for cube mapping

This commit closes #106, #107

Changed primitive int types in the texture to the correct OpenGL types and fixed the initialization list of the jpg controller

* setWrap() will now only be called if a wrap value was explicitly set before
* added rare error check

OpenGL object names were misleadingly named context which can be mixed up with
the OpenGL context. Object name is the correct term used in the specs.

* improved compatibility with pure core profiles
* minor typos

- Furthermore, I have added support for normalized attribute values.

Removed static contexts from the opengl object. In future, this has to be handled by our opengl wrapper, which will hold a copy of the gl state on cpu side.
Made all opengl contexts not copyable.
Created a macro for the shared typedefs which directly creates a const version of the pointer.
Started to change some opengl object functions to be non-const although they might not change any class members, because the function still might change something on gpu side. Therfore, returning the context of any opengl object is also non-const now!
Changed the renderbuffer constructor to just create the context and moved the rest to its corresponding controller.
Removed own type enums in opengl objects => ONLY use the orginial GLenums here!

* Added additional OpenGL error checks
* OpenGL error checks are better usable with namespaces
* Removed checks for OpenGL objects == 0 which would get ignored by OpenGL anyway and are rare
* Added comments
* improved OpenGL ES compatibility