Resize a tab only if the new size of the window is not equal to its current size

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• Changesets:
  • Revision b46f0f5e by mathieui on 2014-05-03T00:27:19Z:

Fix #2072 (only resize a tab if the size changed since the last display)

• Revision 9c8d5777 by mathieui on 2014-05-05T18:01:04Z:

Revert "Fix #2072 (only resize a tab if the size changed since the last display)"

This reverts commit b46f0f5e266c321632738ca40839759486b47a7e.

Conflicts:
	src/tabs/muclisttab.py

Doing this made the unresized elements refresh in the old subwins,
causing glitches and weirdness. And anyway, the only problematic
element is the TextWin (rebuilding all the lines of a buffer is
expensive), but it already checks if the width changed.