Created by: mkszuba
As otter_env_core.sh stands, running otter overwrites whatever might have been present in $PERL5LIB. This is a problem e.g. if one uses this variable to make Perl aware of the install directory used by cpanminus. This PR ensures that the original value of PERL5LIB is preserved.
This is related to the otter-client PR Ensembl/otter-client#1.