1) matitaMathView.ml splitted into cicMathView.ml + matitaMathView.ml
2) interface of matitaMathView.ml and cicMathView.ml greatly simplifed
so to avoid any reference to the textual/MathML datatypes.
3) up to the problem of taking screenshots, the file matitaMathView.ml
is now oblivious of the difference between text and MathML. It will
be soon possible to switch between text and MathML simply by changing
the implementation of cicMathView.