Argh. Realize we already have equivalents of initCli() and finishCli()

Argh. Realize we already have equivalents of initCli() and finishCli()
- rpmcliInit() and rpmcliFini() do almost exactly the same as our
  newborn cli-helpers, but they've been almost unused until now.
  Use them and lose the new ones.. doh.
- The downside is that popt aliases are now broken when running commands
  from the build tree due to lt-foo in argv[0], whereas initCli() took
  and explicit popt context name argument. Oh well...
- rpmcliFini() was missing several necessary memory cleanup calls,
  add them there while at it.