[mms] Disable advanced functions if using POP3 driver (caching, on-demand
filtering, searching, sorting) because it is too resource intensive.
[mms] Use native PHP code for POP3 driver (c-client no longer required).
-[mms] All native IMP code now uses exceptions instead of PEAR_Errors.
+[mms] IMP code now uses Exceptions instead of PEAR_Errors.
[mms] Fix wrong charset on filenames when stripping attachments (Bug #7220).
[mms] Use effects queue to prevent issues with users clicking on effects
elements too quickly.