Get rid of probe_geometry_columns (typmod support) and other obsolete

[robe]

All this function did was to inspect the geometry_columns table and notify of stale entries and add missing entries.

Now that geometry_columns will be a view in 2.0 and we also have typmod, this function and the rest of it's kind are completely irrelevant.

We hadn't marked it for deprecation, but it seems necessary to completely remove it or keep it and have it do nothing except to show a notice that says:

"I do not do anything anymore, get with the program"

I'd just assume drop the function entirely.

There are some dumb ones like rename_geometry_table_constraints() which I didn't even know existed but already does nothing but to tell you it does nothing.

These I have decided to just add to legacy but strip them of their functionality so they just return a "I am obsolete message". Just for those people with old code lying around that happen to call these things.

Functions in this family so far are:

rename_geometry_table_constraints(); fix_geometry_columns(); probe_geometry_columns