OGL: add check_gl_error function
OGL: add error checking to ShaderProgram
OGL: reset shader id on unload
OGL: track linking status of shader program

(GL_LINK_STATUS means something different)
OGL: either load all shader parts or none
UMVE: use util::fs api to get home dir
UMVE: fix shader load order
Merge pull request #85 from Waldteufel/umve-fix-shader-reload

Fix shader reload
DOCS: Enable search bar in Doxyfile
Merge pull request #86 from kdex/doxygen-search

DOCS: Enable search bar in Doxyfile
UMVE: make example plugin compatible with Qt5
Merge pull request #87 from Waldteufel/qt5-plugins

UMVE: make example plugin compatible with Qt5
MESHCONVERT: fix typo with util::ArgResult usage

next_result can return a NULL option, next_option would be correct
Merge pull request #88 from Waldteufel/meshconvert-args

MESHCONVERT: fix typo with util::ArgResult usage
DMRECON: use math::algo::round
Merge pull request #90 from Waldteufel/algo-round

DMRECON: use math::algo::round
UMVE: use get_home_dir instead of getenv
Merge pull request #89 from Waldteufel/umve-homedir

UMVE: use get_home_dir instead of getenv
UTIL: Disallow copy of AlignedMemory
Merge remote-tracking branch 'upstream/master'