Add support for marking blocks by row, column as well
Rename: shorter function names
Add tests for new arbitrary marking
Refactor some logic into the model; document some things
Only redraw highlight canvas when marking -- should improve performance
Fix a bug, document mark(), unmark()
Move hidden input around to match position of cursor
Unfocus text input on every drag start
Remove unnecessary change, add comments
Rename markedBlockKey to nextMarkedBlockId
Merge pull request #22 from dabbler0/moving-hidden-input

Move hidden input around to match position of cursor
Merge pull request #20 from dabbler0/arbitrary-highlight

Add support for marking blocks by row, column as well
Merge pull request #24 from dabbler0/clean-unfocus-everything

Unfocus text input on every drag start
Merge remote-tracking branch 'upstream/master'

* upstream/master:
  Rename markedBlockKey to nextMarkedBlockId
  Remove unnecessary change, add comments
  Unfocus text input on every drag start
  Move hidden input around to match position of cursor
  Fix a bug, document mark(), unmark()
  Only redraw highlight canvas when marking -- should improve performance
  Refactor some logic into the model; document some things
  Add tests for new arbitrary marking
  Rename: shorter function names
  Add support for marking blocks by row, column as well
Update to latest.