[with patch, positive review] conjugate() in sage-4.0 is broken

[gmhossain]

1) pynac .conjugate() method returns wrong answer:

f(x) = function('f',x)
f(x).conjugate()

f(conjugate(x))

Above is certainly not true. For example: f(x) = I + x implies f(x).conjugate() = -I + conjugate(x) which is not equal to f(conjugate(x))

2) view() causes SIGSEGV crash

f(x) = function('f',x)
g(x) = f(x).conjugate()
view( g(x) )
boom!!

[burcin]

I have a fix for (1) above, don't know about (2) yet. Same issue effects .real_part(), .imag_part(), etc. functions.

[burcin]

This is fixed in the new pynac package here:

 http://sage.math.washington.edu/home/burcin/pynac/pynac-0.1.8.p0.spkg

Since the package also contains fixes for #6256 and #6211, the doctests should be run with those patches applied.

Besides adding doctests for the fix, the patch cleans up symbolic functions and adds correct conversions for asin, asinh, acos, acosh, and atan.

Nick, can you review this?

[ncalexan]

Fine by me.