(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, add comments, and re-org.

Added macros for log_level::trace.
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.