Replace QtGui include with individual includes

Qt 5 splits QtGui into Gui and Widgets components. Including the
individual includes will solve this problem.
Merge pull request #1291 from simonsonc/qtgui-include

Replace QtGui include with individual includes
Expose outline join style as a parameter for simple fill symbol type
osgeo4w: try ALL_BUILD twice
Typo in Processing
[tests] Fix composer tests. Rebuild images following MTR rendering changes. Switch tests to use standard test font.
fixed processing plugin customization (thanks to Martin Dobias), fixes #9134