This patch addresses the following problems with Breach3:

Importing Breach2 or Rules of Engagement 2 leaders. To do this, examine any
existing Breach 3 squad leader, click on the Import button, select which game
you're converting a character from and where on your drive the relevant files
are, and click OK. The new, converted Breach 3 leader is now saved and shown.
 
The game could occasionally crash when a medkit was used.  

Small, scattered 'drops' of terrain were sometimes wrongly displayed on the
sensor map during a limited visibility game.

Animations could not be attached to terminators in the builder.

A remote charge would become a proximity mine if dropped and picked up again!

Beasts sometimes behaved weirdly when facing a lone, unfiring Squad Leader. 

The Campaign Debriefing window: this was incorrectly headed Mission Briefing,
and sometimes wrapped text incorrectly.

A small graphical change has been made to the Builder's Equipment Pool screen.

The game now asks for confirmation if you start a mission without equipping
your men, or if you leave the entire Builder section without saving.
