MapList now uses synchronised lists.
MapList now uses synchronised lists.

Added explicit documentation on synchronisation.
Minor code tidying and typo fixes.

Fixes issue 4344.

Change-Id: I92b691de235cb5da1ca83133cb6eac451c5973bd
Reviewed-on: http://gerrit.dmdirc.com/1452
Automatic-Compile: DMDirc Local Commits <fd7610eb81751244add0a62da2de7da51cfdce47@googlemail.com>
Reviewed-by: Gregory Holmes <79e2475f81a6317276bf7cbb3958b20d289b78df@dmdirc.com>

DMDirc/Util