LIBDRUM-161. Configure dspace to use solr-env.

Updated dspace solr configuration.
Updated documentation with new installation procedure.

https://issues.umd.edu/browse/LIBDRUM-161
Merge branch 'feature/LIBDRUM-161' into drum-develop
LIBDRUM-165. Statistics (Custom) - Monthly page generates an error.

Updated installation instructions.

https://issues.umd.edu/browse/LIBDRUM-165