math: fix declarations regarding matrix diagonals
Merge pull request #84 from Waldteufel/matrix-diagonal-rename

math: fix declarations regarding matrix diagonals
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
[draft] make some parts work with VisualStudio
[win32] dmrecon: don't use round (C++11)
[win32] mve: use binary mode for binary ply files
[win32] libs/ogl: Use find scripts for OpenGL and GLEW

Fixes compilation using Visual Studio 2010 x64.
[win32] add jpeg and tiff support
[win32] Implement libpng support