Improved doc for index attribute
Added isFirst method
Added getHunkStartLines method
Renamed contentView.renderCommitBySha to .renderBySha
First draft of contentView.renderFullDiff() before refactoring the rendering of a single hunk
Refactored inner loop of .renderHunks() into separate method .renderHunk()
.renderFullDiff() now skips lines that have already been rendered by .renderHunk()
Cleaned up .renderFullDiff()
Simplified continueAtLine logic