Update Python hashbang to respect environment

The /usr/bin/python hashbang causes doc builds to fail when Python3 is
the default Python and Python2 is being used from within a virtualenv or
Pythonbrew environment.

Signed-off-by: Sharif Olorin <sio@tesser.org>
doc: Add "nearest power of two" to PG rule-of-thumb

Following an IRC discussion, it emerged that it would be helpful
to explain the merit of choosing a number of PGs per pool that is
a power of two, to keep PGs at roughly equal sizes in case of
PG splits.

See http://irclogs.ceph.widodh.nl/index.php?date=2014-03-12 for the
original discussion.

Signed-off-by: Florian Haas <florian@hastexo.com>
Merge pull request #1438 from fghaas/doc-fix

doc: Add "nearest power of two" to PG rule-of-thumb

Reviewed-by: Sage Weil <sage@inktank.com>
Merge pull request #1423 from fractalcat/respect-python-env

Update Python hashbang to respect environment
doc/release-notes: note that WATCH can get ENOENT now

Signed-off-by: Sage Weil <sage@inktank.com>
mailmap: Danny Al-Gaaf name normalization

Signed-off-by: Danny Al-Gaaf <danny.al-gaaf@bisect.de>