[ghemical-devel] constraints added

[Tommi Hassinen]

Hello,

the constraints are now added ; the only impementation is now for the 
tripos force field (the default one) ; I will add other implementations 
later (and perhaps also for QM engines).

The constraints have the added flexibility of (optionally) separate 
minimum and maximum distances. The "project view" is not yet fixed to show 
the two values ; Donald can you add this fix?

Regards,

 	Tommi