[DS-1832] Proxy configuration set in system properties if empty
DS-1841: adding example files for agent and domain-based spider filtering, borrowed from OSU Libraries, with much thanks
Merge pull request #431 from hardyoyo/DS-1841-add-examples-for-spider-filtering-by-domain-and-agent

DS-1841 adding example files for agent and domain-based spider filtering
Update documentation
[maven-release-plugin] prepare release dspace-4.0
[maven-release-plugin] prepare for next development iteration
Update master branch to next major release
[DS-1744] Upgrade to latest log4j
Merge pull request #428 from KevinVdV/DS-1832

[DS-1832] Proxy configuration set in system properties if empty
DS-1757:Missing images in mobile theme

Removed link to mobile-default-thumbnail.png and changed to default-thumbnail.png which already existed.
Added contextPath 

Added context path per helix84.
Merge pull request #435 from misilot/patch-2

DS-1757 Missing images in mobile theme