-  Find all the remaining bugs!

-  ES_LEFT, ES_RIGHT and ES_CENTER.  ES_RIGHT and ES_CENTER cannot be
   used with single line edit controls or be combined with ES_AUTOHSCROLL.

-  Hide selection when window loses focus and ES_NOHIDESEL to disable
   this functionality.

-  ES_LOWERCASE and ES_UPPERCASE.

-  ES_PASSWORD and EM_PASSWORDCHAR.

-  ES_OEMCONVERT.  Probably won't do anything very much.

-  ES_READONLY.

-  ES_WANTRETURN and Ctrl-Enter to move to next line when this
   functionality is enabled.

-  Implement undo buffer correctly.  Windows allows the user to undo
   entered text as well as deleted text.  You can also undo an undo.

-  Add word wrap - this is a very big change!