fix <a href="http://drupal.org/node/48376">48376</a>,  <a href="http://drupal.org/node/42095">42095</a>,  <a href="http://drupal.org/node/34976">34976</a> (but this new feature is untested)

Fixed bug 46316 (I think) and fixed error checking problem for manual entry of lat or long in gmap_user

A few bug fixes, optimizations and a relatively minor change to the macro creator that makes it way more useful.

Major revision.  Includes using xmaps library, map of users, and major improvements to API (for more generalized use) Compatible with Drupal 4.7 only.