Add 'list --matches' example to man page.

Also add some vertical whitespace around examples.
1132981: Fixed exit code when registering system with no products installed

- When registering a system that does not have any products installed via
  consumerid or activation key, the system will no longer return an exit
  code of 1.
Merge pull request #1090 from candlepin/crog/1132981

1132981: Fixed exit code when registering system with no products
Merge pull request #1088 from candlepin/alikins/man_page_misc

Add 'list --matches' example to man page.
1122530: Removed/updated more obsoleted documentation, dates and versions

- Additionally, some minor grammar corrections have been made.