suppressing int calls from exponential units
suppressing int calls from exponential benches
suppressing int calls from exponential covers
polishing includes and adding invalid guards in exponential functors
adding a logeps constant
speeding expm1
adding exhaustive tests in exponential
correcting includes in some files and adding a second parameter to expx2 to fit cephes
adding/modifying some exhaustive tests
adding some tests for pow family
guarding invalids in the powxxx functions
wrong doc for one param expx2
error in nthroot for negative first param
first comment line had vanished from sone test files
log2 and log10 must still have int tests
Merge pull request #693 from jtlap/polishing_exp0

Polishing exp0