fix Qt5 porting issue, not complete

1. replace Q_WS_* with Q_OS_*, because Qt5 remove these macros already.
2. add Q_OS_* macros to moc when compile, qmake will add for themself,
but not cmake.
Qt5 porting issue fix for mac, not complete

1. Qt5 can't find QT_MAC_USE_COCOA
2. Qt5 remove QMacCocoaContainer from mainstream, but still leave
header on include directory, should use external project "qtmacextras",
it's confused me a lot!!!
3. Qt5 changed moc include name strategy, mix cpp and objc method is
different, separate headers should be used.
fix qt5 porting issue for mac

1. fix bundle building issue
2. disable mac native search field cause qt5 can't support it currently.
3. use qt5 native scrollbar, it's more like mac native scrollbar.

Still need working:
1. scroll on document list speed is poor on mac! use pixmap cache for
drawing instead!
2. mac fullscreen is supported on Qt5, use native solution.
3. mac native toolbar is not supported by Qt5 currently(Qt5 v5.1.1).