Many cleanups on the host class.  For example, tasks and inventory, as there should only ever be one at a time, will not call the current function as it's not really necessary.  The only item found is stored so we can use set method rather than add.  Relevant files updated to maintain functionality throughout.

git-svn-id: https://svn.code.sf.net/p/freeghost/code/trunk@2361 71f96598-fa45-0410-b640-bcd6f8691b32