Persist custom log settings over a restart

[binduwavell]

There are some cases where it would help if the logging specified in support tools persisted over a reboot. This could be to help debugging issues during startup or for less technical folks so they don't need to mess with log4j properties files.

[AFaust]

Using some of the features required for #55 it should be easy to transparently persist changes made to the original Log4J configuration in a persistent file (might need to be external to temp or work directories to avoid potential deletion during restart). A special bean would need to be added to the Spring context in such a way that it directly follows initialisation of the Log4J hierarchy. This might require use of depends-on both in our bean as well as a key bean in the Alfresco startup order to force this restoration of previous runtime configuration as early as possible. Technically there should be no reason why we cant make the initialisation of the Log4J hierarchy and our restoration the first thing to be done when the Spring context starts up - it is only an oversight by Alfresco that the Log4J hierarchy isn't initialised as early as possible...