Fixed compatibility with GLM versions >= 0.9.9

[ghost]

Fixes the following error when using GLM >= 0.9.9 with oglplus:

/usr/local/include/oglplus/interop/glm.hpp:71:1: error: ‘glm::precision’ has not been declared

• https://github.com/g-truc/glm/commit/a7b72ec renamed glm::precision to glm::qualifier
• https://github.com/matus-chochlik/oglplus/blob/b2279685333a9eec588b64bf4bc983be8854b05a/include/oglplus/interop/glm.hpp fails to compile with glm versions including and after this commit
• this PR conditionally uses the new glm::qualifier for versions >= 0.9.9
• tested with https://launchpad.net/ubuntu/+source/glm/0.9.7.2-1
  • worked previously and still works
• tested with https://launchpad.net/ubuntu/+source/glm/0.9.9~a2-2
  • did not work previously and works now