reduce PyFnWriter compile time (pywriter) by 75%

reduce PyFnWriter compile time (pywriter) by 75%

needs some explanation: the pagereader enumerates all the sub-options
(Rc=1, OE=1) and adds one instruction (each) for all of the sub-options
but adds the exact same pseudocode.

PyFnWriter then generates up to *four copies* of the exact same pseucodode
and four functions, *only one of which is actually used* by ISACaller
(the one *without* Rc=1 and OE=1), then handles Rc=1 and OE=1 *separately*

added an option to pagereader to only add the first-encountered instruction
but for other purposes it is still added, so is not made the default