* include.el: Purge deprecated rhtml-mode. Add robe-mode and mmm-erb-mode
  for *.html.erb files editing.

* main.el: Fix faces. Update popwin-el support according to 0.7 release notes.
  Add shell-mode support. Update ruby-mode support with robe-mode and mmm-erb-mode.
  Minor file refactoring. Add useful `what-face' function. Fix `dired-find-file-appender'.