first draft of left join
join with repeats
Join takes optional keyword argument
add Join docstring
pep8
Join: py3 fixes
join: add test for missing element
add left and right defaults to join
remove apply keyword argument from join
join: use vacation example for docstring
join: expand docstring to include left_default and right_default
py3 fix
add join to API
add join benchmarks
join: interleave key and seq arguments

suggested by @karansag
join: support non-callable keys with ``get``

Suggested by @karansag
pep8
join: faster get in case of raw index
rename _simple_get to getter
side->sequence in join docstring