(CFACT-58) Implement mountpoints and filesystems fact for BSD/OSX.

Implementing the mountpoints (structured) and filesystems (flat) fact for BSD/OSX.

The filesystems fact lists the mounted file system types.

The mountpoints fact is a new structured fact that describes the mounted file systems in detail.
(maint) Fix missing documentation in logging header.

Fixing missing documentation in logging header.
Adding a missing doc comment for a define.
Moving some BOOST constants into the .cc.
Fix /* to /** to properly treat the comments as doxygen comments.
(CFACT-58) Implement mountpoints and filesystems facts for Linux.

Implementing the mountpoints (structured) and filesystems (flat)
facts for Linux.

The filesystems fact lists the file system types supported by the
kernel.

The mountpoints fact is a new structured fact that describes the
mounted file systems in detail.
(CFACT-58) Implement the Linux partitions fact.

Implementing the partitions fact for Linux.

We also implement the following attributes for each partition:

* partuuid - The partition UUID (as opposed to the filesystem UUID).
* label - The partition's label.

This takes a new build-time dependency on libblkid (blkid was a
runtime dependency of Ruby Facter).