(CFACT-131) Fix block size calculation for mountpoints fact.

Currently the optimal transfer block size member (f_bsize) was
being used in size calculations instead of the fragment
size member (f_frsize) on Linux and Solaris.

The fix is to use f_frsize instead of f_bsize where appropriate.

Additionally, the Solaris mountpoints fact was not correctly being
populated because it copied a restriction coming from the Linux
implementation.  It was also using a 32-bit version of statvfs,
preventing large file systems from properly reporting their sizes.  The
statvfs64 function should be used instead.

Note: on BSD, the statfs struct has f_bsize as the block size,
as anyone sane would expect.
(maint) Boost 1.57 fix

Ignores warnings from Boost 1.57
(CFACT-49) Finish Windows docs

Adds simplified instructions to README. Removes OpenSSL instructions as
they're not needed for any Windows facts.
(maint) Only include rt on Linux

Not present on Mac OS X.
Merge pull request #215 from MikaelSmith/maint/master/boost-1_57-fix

(maint) Boost 1.57 fix
Merge pull request #217 from MikaelSmith/task/master/CFACT-49-finish-Windows-docs

(CFACT-49) Finish Windows docs
Merge pull request #218 from MikaelSmith/maint/master/fix-rt-lib

(maint) Only include rt on Linux
Merge pull request #214 from peterhuene/cfact/131

(CFACT-131) Fix block size calculation for mountpoints fact.