Merge pull request #73 from MikaelSmith/master

(CFACT-47) Retry after read failure, as suggested in POSIX documentation...
(CFACT-48) Add structured uptime fact

This commit adds a new 'system_uptime' fact,
which returns a map including keys for seconds,
hours, days and a human readable uptime.

Also, the existing uptime facts were updated to
take their values from this new structured fact,
rather than resolving them individually.
Merge pull request #72 from whopper/structured_uptime_fact

(CFACT-48) Add structured uptime fact
(maint) Implement directory enumerating utility functions.

Implementing directory::each_file and directory::each_subdirectory for enumerating directory contents.

Replacing existing uses of directory iterators with the above utility functions.
(maint) scoped_resource should not have default move semantics.

scoped_resource should implement the moving semantics to appropriately modify the other scoped_resource such that the original scoped_resource does not attempt to release the resource.
(maint) Move file utility functions into a type.

Rather than creating a sub-namespace from the util namespace,
scope the file utility functions in a type.  This makes it
more consistent with other utility types.
(maint) Implement environment utility class for manipulating environment variables.

Adding an environment utility class for getting and setting environment variables.
This type is also responsible for specifying the platform-specific path delimiter.
(maint) Fix log message casing.

Fixing all LOG_* macro messages to start with a lowercase character for consistency.
(CFACT-43) Implement Ruby API.

Implementing dynamically loading and binding to MRI.
Loading custom fact files into the Ruby VM.
The Facter interop layer isn't yet implemented, so custom facts will currently fail to load.
(maint) Remove dead source code.

Removing fact.cc since it isn't actually being used any more.
Merge pull request #71 from peterhuene/custom/facts

(CFACT-43) Implement Ruby API.