Added RUCE_DB_Load(Write)Entry

1. Added RUCE_DB_LoadEntry(Load wave, roto, rudb to an entry)
2. Added RUCE_DB_WrtieEntry(Write an entry to roto, rudb)
3. Added RUDB format standard(@src/RUDB.txt)
4. Added TestRUDB
5. Added cmake target 'uninstall'
Do not print an error. Return an error code instead.
Error display should better be handled in executables.