(CFACT-138) Implement Google Compute Engine fact.

Implementing the gce fact that returns instance metadata for Google
Compute Engine virtual machines.

The structure of the fact's data is dependent upon the JSON being
returned from Google's metadata endpoint.
(maint) Command line queries should be case-sensitive.

Previously we were lowercasing each query from the cfacter command line.
This prevented us from being able to query map elements that are not all
lowercased.

cfacter should simply be case-sensative from the command line, but
remain case insensitive via the Facter API.
(maint) Fix some missing doc comments.

Fixing some missing doc comments on to_utf8 and to_utf16 utility
functions.
(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.
Merge pull request #212 from melissaanne/master

Update for building cfacter for el5
Merge pull request #210 from peterhuene/gce

(CFACT-138) Implement Google Compute Engine fact.
(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.
(CFACT-144) Add system32 fact
(CFACT-144) Add Ruby structured facts

Adds ruby platform, sitedir, and version structured facts.
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.
Merge pull request #219 from MikaelSmith/feat/master/CFACT-144-system32-fact

(CFACT-144) Add system32 fact
(CFACT-158) Use rb_block_call instead of rb_funcall_with_block.

rb_funcall_with_block was added in a later 1.9.3 patch.  To support all
1.9.3 versions, use rb_block_call instead.

rb_block_call provides the exact same functionality we need, but doesn't
require us to wrap the C func in a Ruby proc.
Merge pull request #220 from MikaelSmith/feat/master/CFACT-144-ruby-facts

(CFACT-144) Add Ruby structured facts
Merge pull request #221 from peterhuene/cfact/158

(CFACT-158) Use rb_block_call instead of rb_funcall_with_block.
(CFACT-159) Add support to build trusty packages