345 new/updated SNDH files (437 subtunes).

We made it! SNDH v4.6 finally hits the streets.

Quick highlights :-

+ Figured out Michel Winogradoff's digi routines, so here's Disc, Turbo Cup & Bumpy
+ Finally Mad Max's "Bittner, Bit, Bit, Bittner" is included
+ Many more unknown Quartet tracks added
+ STNICCC tunes including gwEm's winning entry
+ Missing The Bits music-mon tunes added, sorry
+ Tonnes of XBios-32 added, sorry mk2
+ 505's fabulous Sabotage tracks
+ Many Jovis tri-mod and SSD tunes