moved and renamed check_modified method to comparable.py and
added check modified parameter to diff function
added method to compare lines of modified cells
small fixes
Create line comparator and added tavish's tests
Mock code for line diffs
Merge branch 'master' into js-linebased-diff
Merge branch 'master' into shoosh-newlinediff
Move tests into a test folder
Fix flake8 problems
Merge branch 'js-linebased-diff' into shoosh-newlinediff
Line-based diff works, including UI
Flake8 fixes
Use different example notebooks for diff/merge test scripts.
Merge pull request #127 from Shurouq/newlinediff

Implement line-based diffing UI and back-end.