Implemented Writer->insertEntity

Change-Id: Ib6743169c0d066b69fc77ee3ced7c6249b378808
Removed class registration file and added psr-0 based autoloading

Change-Id: I4f114cd9bef81f6f95f3780c30b305126f754b0b
Removed manual test file registration and added psr-0 based autoloading

Change-Id: I10b14a1dec9c150cc0c1022422942fec44c26210
Wikibase\Tests\QueryEngine -> Wikibase\QueryEngine\Tests

Change-Id: I41f6c93e99879664ea6e7904317c64da2f1f57b8
Added phpunit XML file and bootstrap

Change-Id: I54b23d83fdc9827b4385045dccda1923f7c44f07
Removed pointless usage of MediaWikiTestCase in QueryEngine component

Change-Id: Ie393b24c347e5216d4fb1c3c6a6c28334b463b47
Added non-mw autoloading support to the DataModel component

Change-Id: I8e82015d8f2fbf380b226d3201cb2f7bf65e6a84