add current_line() method for bpython-repl
using bpython history
up/down arrow keys working again
fix last column cleared bug in terminal
integrated completion matches, starting to build info
Syntax highlighting working
update todo list
move out friendly NotImplementedError
fix cpos to make syntax highlighting work correctly
swap up and down arrow to work as expected
note todo
fix rewind previous lines display bug
unhighlighting working, but undo broken
undo works
fix missing trailing colon in def foo(x): from reprint_line
Bringing over work I've done integrating bpython

Merge commit '8ab771acadeee98755f2d854d1e079683b82c184'
Autocomplete isn't working yet, but that's the main thing remaining