Moved wave entry to RUDB. Destroyed Synth. 

RUCE_DB_LoadEntry does not load wav file any more，load wave from RUDB instead.
Needn't use RUCE_DB_WaveWriteEntry while writing RUCE_DB_Entry to file.

RUDB ver. has been updated to 2. Don't support ver. 1 any more.

Added func: int RUCE_DB_LoadExternWave(RUCE_DB_Entry* Dest, String* Sorc, String* Path);
Load a external wave to a RUCE_DB_Entry.