avocado.core.data_dir: Changes in data dir format

Try as much as possible to turn timestamps into the
ISO format. In fact, iso requires hours and minutes
to be separated by a ':', but that makes URLs far
less convenient, requiring escape characters. So
let's replace it with a dot.

Also, put the short ID after the date, so date sort
can be properly done.

Signed-off-by: Lucas Meneghel Rodrigues <lmr@redhat.com>
avocado.job: Reduce the polling time to 0.01s

This is a workaround for the functional suite running
slow, until there's a more proper solution.

Reduce the polling time from 1 second to 0.01 second,
so short lived tests end quicker.

Signed-off-by: Lucas Meneghel Rodrigues <lmr@redhat.com>
avocado.core: Introduce job_id library

Separate the code that generates a job SHA1 on its own
library. It'll make things easier for unittesting and other
needs.

Signed-off-by: Lucas Meneghel Rodrigues <lmr@redhat.com>
[RFC] avocado: Use new job ID instead of UUID

Use a job ID that is a SHA1, similar to git, instead
of the UUID.

Signed-off-by: Lucas Meneghel Rodrigues <lmr@redhat.com>