Fix capone to get the imgFormat with the image so capone can work on partimage files as well.  Make it so Used tasks can be specified by the user.  Defaults to download tasks in particular.  Can be set to allow any tasks to be counted.  Fix session join to have it's own value to test against and test the session join name setting.

git-svn-id: https://svn.code.sf.net/p/freeghost/code/trunk@2580 71f96598-fa45-0410-b640-bcd6f8691b32
Merge svn with dev-branch