Installing OpenCV from apt binary repo instead of source. (#231)

Compilation from sources requires too many resources and it was making
m1.small machines unresponsive about 22% through the compilation
process.
OpenCV is now poart of daq_dependencies. (#231)
Added a lot of libraries to support compilation of daq part. (#231)

This wasn't really necessary at this step - I could have hacked
deploy.sh - but in the grander scheme of things we had to do it at some
point anyway - it might as well be now when we're warmed up with
provisioning.
Don't give up on the first try when trying to connect to a newly opened EC2 machine. (#231)
Stop using monolithic open machine + provision task. (#231)

The reason is that it didn't allow for parallel execution in fab in
order to open more machines in parallel and provision them in parallel.
Added task for opening several EC2 machines in parallel. (#231)

By default it opens a single machine.
Added fab task for running deploy.sh on the AmI nodes. (#231)

We need a separate task for this in order to be able to run it in
parallel on multiple hosts.
Enabling overriding of the manifest for the current host via env.hostname_to_manifest. (#231)
Improving the experiment running by doing most of the work in parallel. (#231)

- opening machines is done in parallel via the boto parameters
- provisioning machines is done in parallel via a fab task
- copying settings.py and services.txt is done serially, but this is a
very quick thingie - doesn't pay off to parallelize it
- running ./deploy.sh on all crunch nodes is done in parallel