add context check example
Merge branch 'master' of github.com:hpicgs/glbinding
allow for release and debug specific compile flags using cmake generator expression
fix gcc compiler flags
Add interface to register external functions (closes #10)
fix msvc compile flags
change output scheme for contexts example
Merge pull request #56 from hpicgs/register_external_functions

Add interface to register external functions (closes #10)
test
test
Use move to save std::functions
Merge branch 'master' into per_function_callbacks
Reduce memory footprint for compilation with reducing the number of callbacks to one