Start process of 0.1.0 -> 0.2.0

	modified:   core/python_plugin.c
	            1. Add '>>>' prompt. Period still there, so entire
	               prompt is now '>>>.', but this at least distinguishes
	               Python mode from Ado mode.
	            2. Better messages when running file fails.
	            3. One typo fixed.
	modified:   core/stata.py
	            1. Add st_matrix and st_view functions.
	            2. Move selectvar option from st_View to st_view.
	            3. Change alternatingCase to underline_names.
	modified:   core/stata_missing.py
				1. Change alternatingCase to underline_names.
	modified:   tests/test_python_plugin.py
	            1. Add tests for new st_matrix and st_view functions.
added st_mirror and StataMirror to stata.py plus small changes

small changes:
    rename st_Matrix to StataMatrix
    rename st_View to StataView
    rename __repr__ to __str__
    fixes in python_plugin.c and stata.py
    remove camel case in test file
added stata_variable and stata_math, added new tests, minor fixes
added way to find Python files and way to pass locals to python.ado
tiny text change
typos fixes and other small changes
small changes in stata_math
removed undocumented class
less restrictive on st_view inputs
fixed error in st_view
documentation partly updated
more documentation updates; version numbers reverted
more documentation updates
improved docstrings; made parameter names match documentation
typos fixed
changed rounding method in stata_math; added properties to StataMirror class
better docstrings and small fixes
Merge branch 'v0.2.0'