Revise pkg-set.8 to use better English.  Sort option descriptions alphabetically, add description of '-e' for exact match.
Revise pkg-set.8 to use better English.  Sort option descriptions
alphabetically, add description of '-e' for exact match.

Open343/pkg,khorben/pkg,skoef/pkg,en90/pkg,junovitch/pkg,en90/pkg,junovitch/pkg,skoef/pkg,Open343/pkg,khorben/pkg,khorben/pkg