Fixes isrequired

The isrequired flag did not support IP6 localhost, nor did it allow
192.168 addresses, normally used for local private networks. Now it does
Merge pull request #532 from Grimston/master

Allow no password on localhost - slight changes
No plugin manager caching in development environment
Merge remote-tracking branch 'origin/master'
Have x-editor use local files again.
Image-only template added to custom menus.
Media-Manager Youtube video default prefs added.
Removed global $style from tablerender()
Merge branch 'master' of https://github.com/aSeptik/e107