Depth validation in planner

[Sergey Starosek]

On Wed, Feb 13, 2013 at 12:35:59PM +0200, Sergey Starosek wrote:
> During testing I've accidentally entered depth of 1000m with 1min duration
> for the first segment. At this point application
> stops responding for a long time and consumes 100% CPU on one of the cores.
> Every focus change makes it even worse.

Surface pressure has to be validated as well. Given a plan with 1
segment (10m/1min) and changing surface pressure to 100mbar makes
Subsurface unresponsive.

Sergey