new transformation (currently equivalent to identity) for tptp driver

programs: type-checking of application is now performed differently to revocer application of logical symbols and A-normal form

It does nothing, but should not disturb the compilation/use of the rest of the system.

meilleur version : prouvé dans why2 par simplify (<1s) Z3 (monoinst) et alt-ergo sauf la po5 en moins de 100s

handling of functions with same name as keywords (e.g. "axiom")

corrected bug in tptp parser (associativity)

Since there is no install target in the makefile, and people can
prefer to use why-cpulimit of why2. We must add the bin directory of
why3 in our $Path when we use why3 in order to get this new
why-cpulimit. (Perhaps it can be backported to why2?)

and solvers called by why (with tptp2why output)