Explains `namespace` aliases
Merge pull request #329 from strathmeyer/master

Explain `namespace` aliases in README
Added a note on setting a header, before and after.
Short example showing how to use multipart form uploads
Prettified comments.
Fix #317: Added headers that returns a hash of parsed HTTP request headers.
use full attribute name for validation
Fix #328: Version can now be specified as both String and Symbol.
Merge branch 'show_full_attribute_name_in_validation' of github.com:alovak/grape
Updated CHANGELOG.
Fix #322: When returning a 406 status, Grape will include the requested format or content-type in the response body.
Fix #60: Mounting of an API on a path.
#190: When you add a GET route for a resource, a route for the HEAD method will also be added automatically.
Added do_not_route_options, which disables the automatic creatioon of the OPTIONS route.
Added a section on authentication with Basic and Digest examples and references to OAuth2 gems.
Fixed typo.
Fixed documentation for mounting on Rails.
Minor layout fixes in README.
Clarified what responds to HEAD and OPTIONS.
Fixed quotes.