Prevent addition of unnecessarily absolute links to self, via External Link textarea tool

• Feature request

Links added in a certain Tiki instance to that same Tiki instance should be wiki links when the target is a wiki page. If not, they should be relative links as much as possible, rather than absolute links. Using relative links eases domain name changes, and facilitates the management of several environments (for example, synchronizing a production environment with a development environment, like nextdev.tiki.org vs dev.tiki.org).

There may be cases where an absolute link is best, but these should be rare. When a user adds an external link to self with an absolute URL - for example "http://tiki.org/Foo" - which starts with one of the Tiki site root's base URL-s - for example "http://tiki.org/" - Tiki should detect the situation and convert to a relative link - for example "/Foo" - unless the user really wants an absolute URL.

One vector through which URL-s are commonly inserted is the External Link tool in the toolbars of parsed text fields. This tool should be modified to detect attempted insertions of absolute links to self and offer the user conversion to relative.

I imagine there should be an administrative preference to control behavior - either automatically convert to a relative link, or prompt users. Should there be more options?
I believe the default should be to prompt users.

This bug has been demonstrated on show2.tiki.org

Please demonstrate your bug on show2.tiki.org