Add/Edit Tests

 * test add feed, basic planet generation, atom and opml validation (currently failed), planet deletion, file perms
 * add problematic feeds and autotest for them
 * run tests on any host set in base_href, not just planeteria.localhost
 * refactor some tests
Better planet/feed creation/editing

 * default add_feed args, save option
 * allow spciefying planet metadata in make_planet
 * document make_planet
 * fix debug message
 * fix bug in passing image value to add_feed