fix vertex attrib binding on windows
fix attrib binding and legacy impl
revisit gpu-particles example
* move identical code to abstract particle technique
* provide num of particles control via command argument
* fix fragment based partices
* disable clear when paused
* adjust particle alpha based on number of particles
revisit examples common
* initialize and rely on glbinding in all examples
* print basis gl infos when ever an example window is created
revisit all examples
* unify example structure
* add more extension checks
* remove unused includes
* remove mac fixes (for now - a better solution is commin)
* unify code style (and use gl and glm namespaces)