new assumptions for inverse trig functions
fixes pyglet doctest problems

fixes TypeError and KeyError exceptions in the pygletplot package

    Traceback (most recent call last):
      File "/usr/lib64/python2.7/doctest.py", line 1289, in __run
        compileflags, 1) in test.globs
      File "<doctest sympy.plotting.pygletplot.__init__.PygletPlot[29]>", line 1, in <module>
        p[2] = -x**2-y**2
      File "sympy/plotting/pygletplot/plot.py", line 320, in __setitem__
        f = PlotMode(*args, **kwargs)
      File "sympy/plotting/pygletplot/plot_mode_base.py", line 164, in __init__
        self.style = self.options.pop('style', '')
      File "sympy/plotting/pygletplot/plot_mode_base.py", line 174, in w
        r = f(self, *args, **kwargs)
      File "sympy/plotting/pygletplot/plot_mode_base.py", line 327, in _set_style
        v = ['both', 'solid'][step_max > 40]
    TypeError: list indices must be integers, not BooleanFalse

    Traceback (most recent call last):
      File "/usr/lib64/python2.7/doctest.py", line 1289, in __run
        compileflags, 1) in test.globs
      File "<doctest sympy.plotting.pygletplot.__init__.PygletPlot[30]>", line 1, in <module>
        p[2].style = 'wireframe'
      File "sympy/plotting/pygletplot/plot.py", line 301, in __getitem__
        return self._functions[i]
    KeyError: 2

Signed-off-by: Thomas Hisch <t.hisch@gmail.com>
remove redundant condtion

We already know that radicals is True since the preceding line
returned if `not radicals` was True.
old assumptions for inverse trig functions
A minor change in tests for new assumptions
remove redundant code and fix typo

The check for the function being zero is part of the standard
'free_symbols' and need not be repeated for the specialized
form of the routine in `_free_symbols`.
Merge pull request #7356 from debugger22/arctrigo

Fixed positive assumption for arc trigonometric functions
Merge pull request #7405 from smichr/polys

remove redundant condtion
Merge pull request #7401 from thisch/pygletdocfix

fixes pyglet doctest problems
Merge remote branch 'upstream/master' into manybody
Finish writing the core functionality code

The code for the core functionality and their testing has been finished
writting. Now it is debugging time. The interface of the features that
has been implemented in the present stage is not expected to change
considerably in the future.