Closes #732: fix some Ada highlighting issues.
Closes #732: fix some Ada highlighting issues.

tomstuart/pygments,tomstuart/pygments,tomstuart/pygments,tomstuart/pygments,tomstuart/pygments,tomstuart/pygments,tomstuart/pygments,tomstuart/pygments,tomstuart/pygments,tomstuart/pygments,tomstuart/pygments,tomstuart/pygments,tomstuart/pygments,tomstuart/pygments,tomstuart/pygments