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 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 zero_padded_statepoint
Moved zero-padding features to string.F90
Fixed zero_padded error message typo
Merge remote-tracking branch 'mit-crpg/openmc/develop' into ptable-resample
Merge remote-tracking branch 'openmc/ptable-resample' into ptable-resample
Fixed overflow error in count_digits
fixed comment that was over 80 characters
check for void material to avoid out of bounds
removed vestigial check, variable
Don't use PWD environment variable when setting path to input files. Closes #302
on github.
Fixed tests for zero_padded_statepoint