Continue to overhaul vim plugins:
1. Add new neocomplete plugins.
2. Add my modified version of xmledit.
3. Remove unused supertab plugin.
Continue to overhaul vim plugins.
1. Add 'vim-airlin', 'neocomplete', 'vim-fugitive' plugins.
2. Remove 'supertab' plugin.
3. Refine _vimrc settings.