Update of Bitfield

- Updated OGLplus Bitfield so that it can be used with enumerations
  from the other libraries.
- Re-used OGLplus Bitfield in EGLplus.
Merge branch 'develop' into feature-boost-python
Fixed a typo in the EGLplus SurfaceTypeBit enum
Merge branch 'develop' into feature-boost-python
Added the IsBitfieldBit helper trait template
Merge branch 'develop' into feature-boost-python
Added default constructor to Bitfield
Merge branch 'develop' into feature-boost-python
Multiple changes to Python bindings

- Reimplemented the export of Bitfields.
- Renamed the file implementig range adapters.
- Updated bindings for Context, Configs.
- Added Surface.
- Other minor changes.