Fixes post 0.10

Making avocado output nicer, standardize output dir naming, and other niceties. Output sample:

    $ scripts/avocado run tests/sleeptest.py --multiplex tests/sleeptest.py.data/sleeptest.mplx 
    JOB ID : 593da82af4b7a90daf434b303b4bbe244c899117
    JOB LOG: /home/lmr/avocado/job-results/job-2014-08-11T17.43-593da82a/job.log
    TESTS  : 3
    (1/3) tests/sleeptest.py.short: PASS (0.50 s)
    (2/3) tests/sleeptest.py.medium: PASS (1.01 s)
    (3/3) tests/sleeptest.py.long: PASS (5.01 s)
    PASS : 3
    ERROR: 0
    FAIL : 0
    SKIP : 0
    WARN : 0
    TIME : 6.52 s