Added Preliminary capabilities to test Task Executor code for the 'full
dag' test case created earlier.
Created mechanism to manage async capability messages (register the
outputs in TE to be used, link with IDs for efficient taskdag lookup)
Core working Task Executor, very ugly though. Still need to add user
input (just in time ie), multiple end points, exit cleanly (trivial)
Code Complete on Task Executor basic functionality. Ugly looking code,
but fully functional. Handles multiple end-points, user inputs and clean
exits with appopriate kill messages.
Merge pull request #8 from Upsham/dev-ukd

Task Executor - Milestone 3 (Code Complete)