Break single CaretPosition into having two caretPositionInternals.
Store caretPositionInternal as (lineIndex, positionWithinLine) pair.
Moved Backspace() as a CaretPosition method.

Experimenting with best placement for the caret moving/editing
functionality.
Use consistent path separator for presentation.

Use OS-specific path separator internally only.
Make note of cleanup result for debugging.
Made GetDocPackage return err instead of panic, for status page.

Update to new go.tools api.
Fix cursor target x not being updated.
Create simpler internal API for text editing operations.

Simplify Backspace operation.
Add CreateSelectionIfNone(amount int32), ReplaceSelectionWith(s string).
Add caretPositionInternal.willMoveH(amount int32).
Replace caretPositionInternal.EqualPosition with Compare.
Add LenContent() int to MultilineContentI.
Restore functionality of cut, copy, paste using new api.

Fix bug in willMoveH where it wasn't counting newline character.
Restored functionality of jumpWords, CenterOnCaretPosition.
Make note of future type improvements.
Avoid using unexported func.
Use LenContent(), add todo comments.
Remove willMove because willMoveH supersedes it.
Merge pull request #1 from shurcooL/caret-position-refactor

Caret position refactor.