bugfix: --skip-packages activated --skip-files (refactoring typo)
tklbam-backup: fix --skip-files handling
fix regression: mysql_fh under --simulate needs to be open in write mode
restore terminology: OVERLAY => FILES OVERLAY (less ambiguous)
dump /TKLBAM metadata directly to dump_path

rational:

- Faster: Why should we have to copy /TKLBAM over to --dump-path at all?
- We might not have enough space to backup the database on the root filesystem
removed Backup.cleanup method

rational: doesn't provide a useful abstraction because the details regarding
extras_paths (whether or not it's dleted, and under what conditions) are
exposed in cmd_backup.py anyhow.
chmod 700 extras_path.path
tklbam-backup UX: make backup verbose and transparent

rational:

1) make it easier to understand how TKLBAM works
2) make it easier to debug and tweak backups
4) make it harder to accidentally skip backing up something important (e.g., a
   database)
explain why we need to copy /etc/passwd and /etc/group into /TKLBAM
explain purpose of /TKLBAM directory
slightly more verbose pgsql database serialization

Limitation: we use built-in pgsql functionality to take care of pgsql
serialization so unlike with mysql serialization we can only call a callback
at the database serialization level.
bugfix: prevent scary psql warning "couldn ot change directory to..."
bugfix: pass usepty=True option to UnitedStdTrap

rational: otherwise unix buffering can cause the output to seem "stuck"
tklbam-backup: print help instructions before executing --debug shell
update backup log in real-time

rational: tklbam-backup's logfile was useless if you were running tklbam-backup
from cron because the logfile would only be written to when tklbam finished. If
it hadn't finished (e.g., it got stuck) the logfile would be empty.

To fix this I added a tee-like mechanism to stdtrap (in turnkey-pylib)
tklbam-backup: moved timestamp creation to utils

rational: we're going to need timestamp for restore as well
renamed util.py functions: _title => fmt_title, timestamp => fmt_timestamp
tklbam-restore: update /var/log/tklbam-restore in real-time
tklbam-restore: revise we're done message to better explain need for reboot
bugfix: fix printing of exceptions tracebacks during backup or restore into logs