Update .travis.yml
(Bug 62150) SMWSparqlDatabaseError Malformed query order by: Unresolved prefixed name

Provided by Giacomo Carnevale (see [0]).

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Added an integrity test.

[0] https://bugzilla.wikimedia.org/show_bug.cgi?id=62150
Merge pull request #215 from SemanticMediaWiki/sparql

(Bug 62150) SMWSparqlDatabaseError Malformed query order by: Unresolved ...
Update SemanticMediaWiki.php
Update SMW_Messages.php

Amended outdated systemmessage
Update RELEASE-NOTES.md
Update SemanticMediaWiki.php
Merge branch 'master' of ssh://wmfgerrit/mediawiki/extensions/SemanticMediaWiki