all: Fix boost's problem with invalid system locale

Boost filesystem library performs self initialization
(lazy since version 1.48). Part of this initialization process
is initialization of locale subsystem.
On systems with miss-configured locales this locale initialization
step throws an exception.
Since internally we do not use any localization facility
we can clear bad system settings that cause locale initialization
to fail.
This patch ensures that locale subsystem can be initialized correctly
and through that allows use of boost filesystem library.

Also fix uninitialized but used variable.

Change-Id: Ia7b24479d38772d0dce4157a8d47bcb3d73bc97f
master: Add option disabling periodic metadata dumps

This commit adds a non-documented option MAGIC_DISABLE_METADATA_DUMPS in
mfsmaster.cfg that disables hourly dumps of metadata in master. It's needed for
testing purposes only.

Change-Id: I12fd96936778b901cc09c1e3822bc9404e8e281f