fixed SC.opt integration with regular HC parser
fixed SC.opt integration with regular HC parser

Only enabled when searching forward.

note : it slighly improves compression ratio,
but measurably decreases speed.
Trade-off to analyse.

unknownbrackets/maxcso,unknownbrackets/maxcso,unknownbrackets/maxcso,unknownbrackets/maxcso,unknownbrackets/maxcso,unknownbrackets/maxcso,unknownbrackets/maxcso