deployment tools only function correctly if executed local to the .assisi file

[rmm-fcul]

As per issue #46 except for assisirun.py and deploy.py.

We expect the execution of all tools to be consistent no matter where they are executed from (of course using an appropriate path, either relative or absolute).

Given the code structure:

base/
    deployment/
        demo.assisi
        <expect demo.py fabfile here>
        <expect demo_sandbox temp directory here>
        sub/
    other/
        deep/

we attempt to execute from the following locations

- 1 base 
  deploy.py deployment/demo.assisi

- 2 base/deployment 
  deploy.py demo.assisi

- 3 base/deployment/sub 
  deploy.py ../demo.assisi

- 4 base/other
  deploy.py ../deployment/demo.assisi

- 5 base/other/deep
  deploy.py ../../deployment/demo.assisi

- 6 /tmp (arbitrary location that requires absolute path spec)
  deploy.py <base>/deployment/demo.assisi

2 is as expected 4 turns out to work ok (hence case 5) 1,3,5,6 all fail with OSError No such file or directory: 'deployment/demo_sandbox'

For the same tests with assisirun.py,

2 is as expected all others fail, with IOError: [Errno 2] No such file or directory: 'test_single.dep'

[rmm-fcul]

note: sim.py works fine from all locations, and since PR #47, collect_data.py operates fine from all locations.