sip, pyqt5: use PYD extension for Python modules
Merge pull request #116 from saghul/python-module-ext

sip, pyqt5: use PYD extension for Python modules
pyqt4: Do not break MSVC builds.
poppler-qt4: Update to 0.26.3
qt4: Increase pkgrel
gettext: Fix relocating support. Big thanks to LRN.
OpenSceneGraph: Update to 3.2.1
m4: New package. Need testing!
bison: New package. need testing!
flex: New package. WIP