h1. GammaLib-00-06-02 release

This is a bug fix release. The following bug fixes are included:

* clang++ compiler precedence is only taken for Mac OS X >= 10.7
* Omit Python checks if Python bindings are disabled
* Enhance OpenMP configuration on Darwin
* Export MACOSX_DEPLOYMENT_TARGET only for --enable-universalsdk
* Improve Python bindings configuration
* Add TEST_ENV_DIR to load library path