shut of trigsimp when using fu

simplify in TR0 calls trigsimp; if fu is being used then calls
to trigsimp if there are trig functions are shut off.  This is
not the best thing (since if there is a single hyperbolic in the
expression, the call to trigsimp will still be made).

Also, I'm not sure what best simplifications are needed in TR0;
the original paper should be consulted.