added version number to VDMUnit v 2.0.0
Fix module in oldself/state name tokens.

Was null. Is now empty string. Needed for lex name token comparisons.

[Issue: ]
improved prob integration to handle frame rules for implicit operations
Merge remote-tracking branch 'origin/symphony/development' into kel/astv2
updated prob integration to support:

b->vdm strings
vdm->b
  named inv types
  record types with inv