* Removed the unnecessary function replace_escaped_spaces (never used)

* Removed the unnecessary function replace_escaped_spaces (never used)
* Changed all instances of replace_spaces to the actual function call
  (removing the silly wrapper function replace_spaces)
* Added a collapseable folder list for left_main.php
* Added the option for it under Options -> Folders

(Sorry that I didn't do this in smaller commits that only did one or two of
the above actions.)

git-svn-id: https://svn.code.sf.net/p/squirrelmail/code/trunk/squirrelmail@1110 7612ce4b-ef26-0410-bec9-ea0150e637f0