Revert "Reverted to first version"

This reverts commit 6342b06816547b1193aeee4d09ac1242d0661032.
Revert "Revert "Updated makefile to allow compilation on systems with certain packages missing.""

This reverts commit 859e4cbd1283ba1da56144cfa5b996b077c8b8f7.
Added back up folder.
Added Cilkview dependency tracking.
Yet to test it.
Added template wf_stack_frame to allow meta data to be accessed before stack_frame() is declared
Added rules within wf_worker to try and identify a root task when it is about to be deleted - unfortunately this is only working 40% of the the time - I'll need to hammer down into the other scenarios.
Adding modified files as I didn't realise they weren't added automatically with last one
Another attempt to determine the root