#1 hyperbolic trig functions

[asdf]

I've ported the basic (i.e., not the arc) hyperbolic trig functions from the latest glibc (currently version 2.7) for double precision values. Also the fmod() function, and expm1() is used by tanh() so I ported that as well.

Very few lines have been changed from the glibc 2.7 versions other than to get them to work with hpgcc.

My goal was to get the c version of expreval (hosted on sourceforge) to compile with as few modifications as possible.

To this end, I've also included some definitions for isalnum() and isspace() in ctype.

[asdf]