v6.46.3. Bugfix. Improvement.

- v6.46.3 July 25, 2013
	- Moved `Base::setDefaults` to `FileMode::setDefaults`
	- Removed superfluous loading logging messages
	- The attributes `parser`, `header`, `body`, and `content` are now set
correctly to `null` instead of `undefined` if there is no data
	- Correctly set meta attributes when also setting default attributes
(bug since v6.42.2)
	- Added support for `outPath`, `outDirPath` and `rootOutDirPath` to be
null
	- Added unit tests for virtual document loading
	- Fixed `removeWhitespace` tester option default
	- Added `contentRemoveRegex` tester option
	- Fixed debug log lines always being `DocPad.log` (bug since always)