#10 MatcherStream restart-logic on full-buffer is off-by-one

[Kostis Anagnostopoulos]

On MatcherStream:lines [394, 420] where it performs the "restart" buffer action when it is full,
it does not copy a complete block but (blockLenth - 1),
and as a result, when the enclosing loops restarts,
a complete Checksum32.check() is needed instead of a simple roll()
config.blockLength-1
into:
config.blockLength

I note that it does not generate an error, but it is not so efficient to restart rolling-checksum on buffer restart.

Reported against svn-trunk: rev 193.