Revert r38876 "(bug 2443) Add image name as alt-text when no caption is provided."
This broke four test cases:
4 previously failing test(s) now PASSING! :)
* Right-aligned image [Fixed between 08-Aug-2008 21:37:38, 1.14alpha (r38954) and now]
* Centre-aligned image [Fixed between 08-Aug-2008 21:37:38, 1.14alpha (r38954) and now]
* None-aligned image [Fixed between 08-Aug-2008 21:37:38, 1.14alpha (r38954) and now]
* Width + Height sized image (using px) (height is ignored) [Fixed between 08-Aug-2008 21:37:38, 1.14alpha (r38954) and now]
Please recommit with fixes to the existing test cases and some new test cases to cover cases where an empty caption is explicitly requested, see https://bugzilla.wikimedia.org/show_bug.cgi?id=2443#c11