Special::Browse avoid access on null dataitem

[skip ci]
Avoid unnecessary content parse in InternalParseBeforeLinks

* Use ParserOptions::getInterfaceMessage to determine whether a parse
request was initiated from Message::parse or not
* Don't perform a parse on an empty text
Merge pull request #545 from SemanticMediaWiki/no-parse-on-msg

Avoid unnecessary content parse in InternalParseBeforeLinks
Add PrintRequestFactory
Merge pull request #548 from SemanticMediaWiki/printrequest

Add PrintRequestFactory
Improve fixtures
Merge pull request #547 from SemanticMediaWiki/fixtures

Improve fixtures
Move some tests
Move additional tests
Merge pull request #549 from SemanticMediaWiki/import-tests

Import tests
PHPUnit 4.2.6 / Remove assertTag with simpler validation
Merge pull request #550 from SemanticMediaWiki/phpunit

PHPUnit 4.2.6 / Remove assertTag with simpler validation
Rename variable
Merge pull request #551 from SemanticMediaWiki/ren

Rename variable
Merge branch 'master' of ssh://wmfgerrit/mediawiki/extensions/SemanticMediaWiki