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.
- rename wxMessageBox, remove redundant arguments to noui/qtui calls
- also, add flag to force blocking, modal dialog box for disk space warning etc
- clarify function naming
- no more special MessageBox needed from AppInit2, as window object is created before calling AppInit2
- Overall, this is better design
- This fixes problems with the address book UI not updating when the address book is changed through RPC
- Move Statusbar change detection responsibility to ClientModel
This introduces two new source files, keystore.cpp and wallet.cpp with
corresponding headers. Code is moved from main and db, in a preparation
for a follow-up commit which introduces the classes CWallet and CKeyStore.