remove qtgui include in qucs, syntax, schematic
remove qtgui include in exportdialog
remove qtgui include in diagrams/marker
remove qtgui include in diagrams/diagramdialog
remove qtgui in main directory
remove qtgui include in dialog/cppfile
remove qtgui in diagrams/cppfile
remove qtgui in components/cppfile
adjust math.h include
Merge pull request #99 from yodalee/issue93-clean-qtgui-include

Issue93 clean qtgui include