correct number of Plotpoints option
replace Plot3D example with a better looking, faster one
Avoid infinite recursion formatting (a+b)[x] (issue #151)
Parenthesize f[a] in f[a][b] if necessary (issue #151)

Fixes missing parens when formatting (a+b)[x]
Add tests for issue #151
Fix precedence when parenthesizing heads

Just set this to 670, as it looks like this is the value that
Mathematica uses.
basic unittesting
run unittests with setup.py test
add parser unittests
add simple console unittests
replace unittest with unittest2
only import unittest2 for python2.6
add setup.py test command
sympy.Real -> sympy.Float
fix setup.py import mathics circular dependency