update field names to snake case instead of camel case;
change field name "gender" to "sex"
use new solr field names;
create constant class to encapsulate the names against further change;
use the name "sex" instead of "gender"
manually merge in changes from master
human2mouse symbol core on build_indexes_ci has semantics for default
field *, but build_indexes does not (why..?)  Revert until this is
resolved
Merge branch 'master' of https://github.com/mpi2/PhenotypeArchive.git
Merge branch 'change_solr_field_names'
Merge branch 'master' of https://github.com/mpi2/PhenotypeArchive.git