Use -include instead of -include_lib

As the include file is located in the same application, using
-include instead of -include_lib removes the need for the
code directory to be called "lager" or "lager-VSN".

Performance improvement in date formatting function.

The micro-benchmarks show up to 20x improvement, which further
reduces logging overhead.

Changed the messages sent to the backends to include metadata and separated formatting from the backend

Helps with pattern matching.

I didn't want the lager_log_message record being used across application
boundaries, this will insulate other applications from any changes to
the message type's internal structure.

Add informtion about loggly backend

Use quickcheck to test for formatting equivalenve with io_lib

Various bugs uncovered during this testing were fixed and added to the
test suite.

adding css for edocs; also adding edoc pointer to README

Had to add a pseudo-ternary operator to the formatter to support this.
Also allowed lager:log to log metadata.

update rebar to 2.0.0

Add support for a custom log truncation size compile time flag

Added lager:start() to the README

Direct the console logger output to user

Added CRs to the LFs in lager_console_backend

Also removed commented out code.

There are still differences between the erlang io_lib and the trunc_io in
how ~p/~P are handled, but a first step is useful here.

Handle uncaught throw error messages better