Add AbortAndRestart example

A small example handler that demonstrates the AbortAndRestart
functionality.

It creates and runs an Async with a payload function that has a 50%
chance to throw an AbortAndRaise Exception or complete successfully.
Fix callback mocks on test_AbortAndRestart.

The callbacks were not even close to being specified correctly before.
This has been fixed and the test is not more correct that it was.
Fix defaults decorator in grep example

Move defaults decororator from build_and_start to grep in order to
correctly launch the success callback.
Merge pull request #46 from tannermiller-wf/abort_and_restart_fix_test

Fix callback mocks on test_AbortAndRestart.
Merge pull request #47 from tannermiller-wf/grep_fix_callbacks

Fix defaults decorator in grep example
Add further explanation to abort_and_restart example
Fix the broken batcher example

The CAS needed to do a gets instead of get. Also needed to check to do an add
first as the cas will fail if the key doesn't already exist.

Also fixed a syntax bug in the javscript portion of the template.
Merge pull request #50 from beaulyddon-wf/fix_batcher_example

Fix the broken batcher example
Merge branch 'master' into abort_and_restart_example

Conflicts:
	example/__init__.py
Merge pull request #45 from tannermiller-wf/abort_and_restart_example

Add AbortAndRestart example
Merge branch 'master' into add_abort