Make passgen command a little more useful.

Allow users to prepend stuff to the passwords by appending an argument
to passgen. Intended to make it easier for people to keep track of
peering passwords.
Fix index out of bounds error
Merge branch 'feature-passgen' of github.com:ryansb/cjdcmd into ryansb-feature-passgen

* 'feature-passgen' of github.com:ryansb/cjdcmd:
  Fix index out of bounds error
  Make passgen command a little more useful.

Conflicts:
	misc.go
Merge branch 'master' of github.com:inhies/cjdcmd

* 'master' of github.com:inhies/cjdcmd:
  Oxford comma.