Maintenance on bundles, new mapping for date.

Updated all submodules; attempted to resolve the "new" commits in the
surround.vim bundle; added a provision in the .gitmodules file to ignore
dirty submodules; added a new mapping in vimrc to insert the current
date; added provision to set cursorcolumn and text wrapping to column 72
when editing git commit messages.
Adjusted the shortcut for inserting the date

The keyboard shortcut that is used to insert the current date (leader-d)
is updated to place the cursor on the next line after the operation is
complete.
Adjusted the mapping for inserting the date

Changed the mapping that inserts the current date such that it no longer
stops and places the user in insert mode.  The cursor is now simply
placed, and that's it. (It's the difference between o and j)
Undid Previous Submission

Undid commit #080cbaab06c01606d2a04331aee757160ab63756.
Create a new function for vimgrep, adjusted README

Created a new function that is able to do the following:

    - In Normal mode, search the current file using vimgrep for the word
      under the cursor.

    - In Visual mode, search the current file using vimgrep for the text
      that has been selected.

The replaces the old function, which only did the former.

In addition, the README file has been updated to include what will be a
new section containing a maintained list of all custom commands and
keyboard shortcuts.  Right now, this is just in comments, but will be
made live at some point.
Merge branch 'master' into experimental