Make many scripts in src/utils Python 3 compatible.
don't resample ptable xs if diff temperature but same E
set last prn of a nuclide whenever a prn is needed
Merge remote-tracking branch 'mitcrpgopenmc/develop' into ptable-resample
Merge remote-tracking branch 'mit-crpg/openmc/develop' into ptable-resample
Added particle restart case for fixed_source runs
Fixed the fixed_source seed and updated the tests
Make sure Nuclide%energy is deallocated.
Merge branch 'release-0.6.0' into develop
Added zero-padded statepoint names
Wrapped batch number zero padding into a function
Added zero padded filenames for source files

Also correcteted statepoint filenames in write_source_point
Updated tests for zero padded filenames
Commented zero_padded_batch
Merge branch 'develop' into restart_fixed
Corrected tests for fixed_source particle restarts
Merge branch 'develop' into zero_padded_statepoint
Moved zero-padding features to string.F90
Check for energy-dependent multiplicity in ACE file.
Merge pull request #296 from paulromano/multiplicity

Check for energy-dependent multiplicity in ACE file

All tests pass; merging and closing.