DS-1823 move dspace.url to build.properties

dspace.url is now independent from baseUrl
add context to  two methods parameters  to have monthly statistics localised
Select the collection already selected in the previous operation
First pass at a third-party plugins directory
Factor the loader out of PluginManager, and provide a minimal unit test.
Add test of loading from a JAR.
Correct loading from JAR.
Fixes DS-2113: JSPUI HTML5 upload should store Bitstreams...
DS-2138 Discovery should get user's special groups (i.e. IPAuth)
XOAI add bitstream description to xoai metadata format
Add sample configuration and document it
XMLUI My Archived Submissions to sort using DB rather than array loop
DS-2180 Fix findBySubmitterDateSorted to work in metadata4all
Fix to avoid connection pool exhaustion for slow downloads and big files
Move XMLElement of community.subcommunities to getter to prevent errors
REST writeStats to reuse existing context
Merge pull request #608 from mwoodiupui/DS-2107

[DS-2107] Provide a place for third-party plugins
Merge pull request #703 from LongsightGroup/DS-2206-rest-bug-fixes

DS-2206 REST - Fix statistics write context abort, and comm.getsubcom
fix db upgrade script name
Merge pull request #640 from helix84/DS-2147-oai-bitstream-description

DS-2147 XOAI add bitstream description to xoai metadata format