Rename mw.uri to mw.Uri + minor fixes:

• Renaming mw.uri to mw.Uri (since it's a constructor)
• Leaked global variable 'g' in _parse() fixed
• Removing unused local variable '_this' in getQueryString()
• Fix documentation (jQuery 'setAttr' should be 'attar')
• Making non-private variables with '@private' comment, private (or "local").
• Using strict undefined comparison (shorter and faster, [[JSPERF]])
• Moving Resources definition from MediaWiki Page section to MediaWiki main section (to reflect directory structure)
• Coding style conventions (mixed spaces and tabs, line wrapping, double/single quotes)
• Remove passing mediaWiki to mw argument (mw is a global alias)
• Passes JSHint

• Removing 404 errors from UploadWizard/test/jasmine/SpecRunner.html

(Follows-up r93781 's move)