Wrap up remaining legacy javascript (IEFixes, wikibits)

Wrap up remaining legacy javascript (IEFixes, wikibits)

IEFixes:

* Take String.prototype.hasClass off the prototype and into
  a local function.

* Removed module definition "mediawiki.legacy.IEFixes" as it
  is not used anywhere (only pollutes the startup module and
  gives a false impression that its dependencies are indeed
  properly being enforced). The file is loaded raw from
  wikibits.js if isIE6 is true.

wikibits:

* Re-ordered to group related methods together.
* Moved up wgBreakFrames so we don't waste any time running
  code if we'll break the frame anyway.
* All properties that haven't been removed to this date are now
  wrapped in mw.log.deprecate.
  - Replaced most with dummy values of the same type.
  - Kept a few ones around to make highly popular method still
    work (such as addOnloadHook).
  - Kept the importScript family of functions unwrapped for now
    as those don't have a proper replacement until users can
    create modules (bug 34958). Though we could promote these to
    mw.util or mw.loader, that would not solve anything and only
    require scripts to be changed again in the future. Can be kept
    as-is for now and is not yet formerly deprecated.
* Created a local reference to the "window" global as it is
  referenced quite often here.

Change-Id: Iab65de1a0a87abad38b834828cd838dfd1c48ba1