Gettin' with the times

Update Rakefile and Manifest.txt to reflect the change of default README
types from txt to md. This ensures that hoe rake tasks such as
install_gem continue to run properly on a newly checked-out repo.
Add example to bin/benchmark_ips

Adding the example given in the Synopsis section of the README to
bin/benchmark_ips. This means that a developer can easily test the behavior
of benchmark/ips by running the script.
Pulling label formatting into IPSJob

Code to right justify the report name is duplicated. Let's pull this
code into IPSJob so that it can easily be referenced.
Typo :(
Pull warmup and run into IPSJob

Benchmark.ips is so big. IPSJob should know how to run a warmup and run
function on it's list of items. Further refactoring needed.
Add more knowledge to IPSJob

In order to easily run the warmup and run methods, IPSJob should know
about the suite, quiet, warmup and time parameters. Add these as part of
the initialization step and utilize in both of these new methods.
Add compare? to IPSJob

It looks better than just compare alone.
Fix run method

Need to actually return the list of reports (d'oh!)
Add compare! to README and benchmark_ips

Add brief documentation about the compare! method to the README, and add
it to the default addition comparision in benchmark_ips to more easily
test that all things are running correctly.
Add configuration options

The Benchmark.ips(5,2) syntax is vague and difficult to understand.
While keeping this syntax in place, add an additional ability to
configure these options within the block itself by calling `config` on
the underlying IPSJob object and pass in a hash with :time and :warmup
symbols. Also add this to README and example script.
Add another method of configuration

Add another way to configure the warmup and times seconds, and add
documentation.
Rearrange things to look and diff better
Add a create_report method to IPSJob

This will allow subclasses to generate different types of reports.
Split IPSJob into separate file

The ips.rb file is getting pretty long, let's pull IPSJob into it's own
file!
Add consistency between warmup and run

The warmup and run functions in IPSJob were listing the setup methods in
different orders, in particular the Timing.clean_env wasn't always being
called right before the test began. Ordring things to be consistent
between the two methods.
Fix speeling
DRYing up Maths

There were a few places where some timing math was scattered about.
Pulled these equations into their own methods, and added more explicit
units onto variables. Also pulled out some conversions into constants.
Add timing and reports instance vars to IPSJob

Since the timing and reports objects were being passed around like a hot
potato, seemed better to have them be instance variables on IPSJob and
have that class manage them.
Pull IPSReport into its own file

I have plans to increase the responsibilities of IPSReport, pulling it
into its own class.
Rename warmup method

Rename the warmup method to run_warmup so that it does not conflict with
the attribute accessor for the @warmup variable.