initial mods to besselj
mods to other methods for besselj
Removed 2-argument Airy func (also from docs), completed optional arguments to first kind Bessel func
Add description of optional arguments to manual, for first kind Bessel functions
docs: indicate Airy functions take complex arguments; tweak optional argument note
Number of arguments in ccall to :zbiry reduced to 7
Add error, underflow detection and optional args to all Airy funcs
Correct placement of error tests in _airy
restore airy(k,x) following discussion with M. Nolta
add optional args to all remaining Bessel funcs.  Update manual
doc/juliadoc