pybind: use find_library to look for librados

Uses find_library to search for librados, rather than using the soname.
For instance, on OSX librados is named librados.2.dylib.

Signed-off-by: Noah Watkins <noahwatkins@gmail.com>
test: Use portable arguments to /usr/bin/env

Don't use the "--ignore-environment" option to env.  It is a
nonstandard GNU extension.  The standard version is "-i".

Signed-off-by: Alan Somers <asomers@gmail.com>
Signed-off-by: Noah Watkins <noahwatkins@gmail.com>
test: Change interpreter from /bin/bash to /bin/sh

Change interpreter from /bin/bash to /bin/sh.  bash is not guaranteed
to be installed on all Unix systems, and it's not guaranteed to be
installed into /bin either.

There are other scripts that specify /bin/bash; they need to be
examined one by one to look for bashisms.  This was the only one I had
to modify to get unit tests working.

Signed-off-by: Alan Somers <asomers@gmail.com>
Signed-off-by: Noah Watkins <noahwatkins@gmail.com>
test: Use a portable syntax for seq(1)

Use a portable syntax for seq(1).  GNU seq has a default INCR of 1, but
BSD seq has a default INCR of either +1 or -1, depending on the other
arguments.  INCR must be explicitly specified for portability.

This bug is the reason that I was running into the segfaults whose
fix I reported as BUG #6510.

Signed-off-by: Alan Somers <asomers@gmail.com>
Signed-off-by: Noah Watkins <noahwatkins@gmail.com>
pybind: use find_library for libcephfs and librbd

Use find_library to avoid assumptions about platform shared library
naming conventions.

Signed-off-by: Noah Watkins <noahwatkins@gmail.com>
Merge pull request #777 from ceph/wip-scripts

Reviewed-by: Josh Durgin <josh.durgin@inktank.com>