Use misc methods of avoiding unnecesary header includes.
Replace int typedefs with int##_t from stdint.h.
Replace PRI64[xdu] with PRI[xdu]64 from inttypes.h.
Normalize QT_VERSION ifs where possible.
Resolve some indirect dependencies as direct ones.
Remove extern declarations from .cpp files.
feature in clang. These macros should primarily be used to
document which locks protect a given piece of data. Secondary it
can be used to document the set of held and excluded locks when
entering a function.