added split support for goto action
fixed type and set default value to 1 to avoid testing error
moved up the split_options
generate list by keys() for join()
fixed wrong title in doc
updated README.rst for use_splits_not_buffers
this is better
added myself to AUTHORS.txt
only need to check the opening direction is correct
make sure it really opened a split window
added tests for checking other goto will perform in only one window, no other split buffer will be opened accidentially
Merge pull request #191 from littleq0903/goto_split_support

added split support for goto action