Refine Synclude.vim.

Add:
	vim/scripts/Synclude/plugin/Synclude.vim
		-Add configurable syntax-matches file path.
		-Rename global variables such that they include "synclude".
		-Add `SyncludeEdit`.

	vimrc, vim/scripts/Synclude/groups.syn -> vim/matches.syn
		-Specify custom syntax-matches file.