This makes all include paths in the GUI absolute.
Many changes are involved as every single source file in
src/qt/ assumes to be able to use relative includes.
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.
Also update URI parsing to fill in this field.
Note that the message is not currently used in any way with the client.
It should be stored with the transaction.
- try to enforce the same style to all Qt related files
- remove unneeded includes from the files
- add missing Q_OBJECT, QT_BEGIN_NAMESPACE / QT_END_NAMESPACE
- prepares for a pull-req to include Qt5 compatibility
