Compile Qt with Dbus support

- with this, Spyder and IPython qtconsole work correctly under KDE.
- The lack of libQtDBus in Anaconda makes Oxygen (the default KDE theme)
to look for it on the system, which causes an incompatible mix between
Anaconda and system Qt libraries.
- Fixes ContinuumIO/anaconda-issues#32
Don't remove Qt plugins on Linux

- Without them Qt can't show gif, jpeg, svg and tiff files.
- Without this support Spyder can't show its icon on the KDE taskbar,
nor a simple throbber (animated gif) while opening an IPython console.
Bump build number
Merge remote-tracking branch 'ccordoba12/qt-no-mix'
Merge remote-tracking branch 'ccordoba12/qt-plugins'
Merge branch 'master' of github.com:pydata/conda-recipes

Conflicts:
	qt/meta.yaml