[svn] Speed up nested comment parsing in D lexer.
[svn] Speed up nested comment parsing in D lexer.

tomstuart/pygments,spencerlyon2/pygments,erickt/pygments,spencerlyon2/pygments,tomstuart/pygments,tomstuart/pygments,erickt/pygments,tomstuart/pygments,spencerlyon2/pygments,tomstuart/pygments,erickt/pygments,spencerlyon2/pygments,erickt/pygments,erickt/pygments,spencerlyon2/pygments,erickt/pygments,spencerlyon2/pygments,erickt/pygments,spencerlyon2/pygments,spencerlyon2/pygments,tomstuart/pygments,erickt/pygments,erickt/pygments,tomstuart/pygments,spencerlyon2/pygments,tomstuart/pygments,spencerlyon2/pygments,erickt/pygments,spencerlyon2/pygments,tomstuart/pygments,erickt/pygments,spencerlyon2/pygments,spencerlyon2/pygments,spencerlyon2/pygments,tomstuart/pygments,erickt/pygments,spencerlyon2/pygments,tomstuart/pygments,tomstuart/pygments,spencerlyon2/pygments,spencerlyon2/pygments,tomstuart/pygments,tomstuart/pygments,tomstuart/pygments,spencerlyon2/pygments