Faster ``minpoly`` using composed sum.

Added power series functions on "ring.PolyElement" objects.
small changes in the documentation; used ``as_int``
continued fractions functionality enhanced and added to ntheory module
solved code convension errors & error raising functionality changed
global variable removed
modified the function continued_fraction_rational_number(numerator, denominator)
new_beta_function
added newline to end of two files
added newline to end of two files
Removed backup file
Indentation error
merge conflicts in gamma_function.py removed
Modified import headers and argindex
Indentation resolved
Changed eval to pass
test_beta_functions modified
import diff added
broke test removed
Merge conflicts for gamma_test file removed
Indentation corrected