games/3omns: Update to 0.2

Commit ded6410 is 0.1-90-gded6410. Already many commits over 0.1
and just 3 commits of documentation updates short of 0.2 so this
is not a significant update.

• Clean up port
• Use release tarball
• Actually declare a lib dependency on libargp.so
• Drop bogus libxml2, glib dependencies; they were also unused in 0.1_6
• Do not install the docs; the man page already contains the same information