rename access control section
rearrange sections

* all configuration documentation consolidated under one section
* other sections shifted around a bit based on my (@jjb's) subjective judgement of importance

n.b. there is redundancy in the configuration options section, which will be consolidated
in a subsequent commit
consolidate rails initializer documentation
consolidated documentation of configuration options
remove note about new home

which is irrelevant in this repo...
create features list

and move description of db profiling there
Learn more section
documentation for middleware reordering recipe

addresses #45
Merge pull request #46 from jjb/readme-improvements

Readme improvements
Update README.md
flamegraph documentation
Merge pull request #47 from jjb/document-flamegraph

flamegraph documentation
Add nil check for SQL result object
Merge pull request #49 from BigGillyStyle/sql_patch

Add nil check for SQL result object
good citizen : reuse Rails' configurable tmp directory

.. because a Rails app can use a custom location for the tmp directory
Merge pull request #50 from alainravet/configurable-tmp-directory

good citizen : reuse Rails' configurable tmp directory
Update README.md

For Rails 2.3.11, I had better luck modifying the render block so that it prints the `path_without_format_and_extension` method instead of `@virtual_path`.

I figured out the method name by looking inside [rails][this]. I think `@virtual_path` is only used in Rails 3?

 [rails]: https://github.com/rails/rails/blob/v2.3.18/actionpack/lib/action_view/renderable_partial.rb#L19
Use ActiveSupport.on_load to defer ActionController, ActionView initialization
Merge pull request #54 from amatsuda/active_support_on_load_hook

Use ActiveSupport.on_load hook to defer ActionController and ActionView initialization
Merge pull request #52 from thescouser89/patch-1

Update README.md