New configs & sub-configs.
Improved sv.py, set g:mdx_config_name here centrally.
Bundles setting changed.
Enhanced :EditConfig & Bug fixes.

* Now :EditConfig can accept 0, 1 or 2 argument.
* Bugfixed, duplicated bundles & unavailable bundle are handled
  properly.
* Renamed plugin/vim_bundle_manager.vim to have the same name as its
  autoload partner.
* Auto clean up g: variables refering bundle config functions after
  bundle initialization.
* New command :MergeConfig to merge sub configs in config file.
Improved config template.

* Use extend() instead of directly set g:mdx_
Config template & configs changed
Improved vimrc settings.

* disable autochdir, use ,cd to change manually.
* adapt status bar & command line height according to the existing of
  'airline'.