refactor call signature tests, use own file (incomplete)
finished with a huge refactoring of call_signatures testing
further call_signatures test refactoring
removed old unused code
remove interpreter test from test_regression
add a separate speed testing file, #181
add a separate docstring testing file, #181
add a separate api testing file, #181
add a separate jedi system testing file, which helps e.g. if imports are correctly used, #181
move cache test to the right file, #181
move some docstring tests, #181
moved more methods out of regression tests, created integration_import and jedi_system, #181
moved more methods out of regression tests, created test_unicode.py, #181
test_regression should not be executable
use jedi.Script.method instead of stupid self calls in tests
remove test.base.TestBase finally, #181
add test_integration_keyword.py to test keywords (moved out of test_regression), #181
documentation and clean up, #181
finally change name of test.base module to helpers.py, fixes #181