(maint) Adding missing doc comments for regex adapter.

Adding missing doc comments to make doxygen happy.
(maint) Prevent loading of ruby if --no-custom-facts is specified.

If the --no-custom-facts option is given to cfacter, don't bother loading Ruby.
(CFACT-56) Implement aggregate resolutions in Ruby API.

Implementing Facter::Core::Aggregate with chunk and aggregate methods.

This allows for aggregate resolution types and conforms to Ruby Facter's
implementation of defaulting to a deep-merge of chunks.
Merge pull request #84 from peterhuene/aggregate/resolutions

(CFACT-56) Implement aggregate resolutions in Ruby API.
(CFACT-66) Remove log4cxx

Replaced log4cxx with Boost.Log. Supports a similar structure of configuring formatted
sinks for output, with filtering based on log_level.
(CFACT-66) Update trace and readme, add comments, and re-org.

Added macros for log_level::trace.
Updated README to reflect removing log4cxx.
Added comments for new functions in logging.
Change logging prefix used for execution output to differentiate it.
Re-organized logging source so only colorizing is OS-specific.
Merge pull request #85 from MikaelSmith/task/master/CFACT-66-replace-log4cxx

(CFACT-66) Remove log4cxx
(maint) Disable warning register-deprecated.

This warning is specific to Clang, and marks register as deprecated.
Boost still uses register, and we're unlikely to (plus it doesn't
cause any harm when it's used), so the warning is now disabled.