- remove default value for parent variable in dialogs, which should appear
centered over main GUI and pass appropriate value
- add some addition NULL pointer checks
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.
- this change allows us to keep the translation without the need to
re-translate any string, when we update the copyright year
- copyright symbol is changed to HTML to ensure we get no encoding
issues and it's removed from the translation string so translators don't
break it by mistake
