This is really big change.
Now XVimSourceView is removed and all the vim related operations are integreted into
NSTextView and its category.
Main operations are impelmented in NSTextView+VimOperation and NSTextStorage+VimOperation
Change VimOperation's metho names to be xvim_ prefixed.
Delete _syncStateFromView call from out side of NSTextView(or DVTSourceTextView)
Because VimOperation category has its variable to track insertion point,
if NSTextView changes its insertion point (when called setSelectedRange from Xcode)
NSTextView's insertion point and our insertion point has broken consistency.
To track insertion point correctly we hook setSelectedRanges... method and call the xvim_syncStateFromView.
Delete unused file.
Delete all the xvim_syncStateFromView calls other than in setSelectedRanges hook.
Fix clipboard=unnamed does not work property when you put some text