Created v1.5 branch for bugfixes.
Fixed typo in comment.
Fixed query type for spatial databases with linear variations in parameters (nearest -> linear interpolation).
Merge from trunk (changes should have been committed to 1.5-stable).
More cleanup of the manual.
Permit zero coefficient of friction values.
Fixed typo.
Disable refinement while Matt works on it. Interface with Sieve refined needs updating.
Adjusted slip-weakening model to include instaneous healing.
Added testing of db property and state variable names in data files (consistency check only).
Added testing of db property and state variable names in data files (consistency check only).
Fixed comment.
BUGFIX: Cleanup of creating velocity and acceleration fields. Move to Python and set scales (scales were set to length scale).
Incremented version (bugfix).
Remove superfluous Fault.poststep() to avoid multiple calls to updateStateVars per time step.
Removed resetting field metadata for state variables (already set by Material).
Added Drucker-Prager fixes to v1.5-stable that should have been done
originally (they were already in trunk).
Added comments on elastic constants.
Changed elasticConsts so that they only get divided by 2 if k != l (strain
indices).  Previously we were also doing this if i != j.
Changed possible values for cohesion so it can be equal to zero but not
less than zero.