Merge pull request #284 from dblock/master

Added a DSL to declare 'error_formatter' in API settings.
Removed error_format, will match the request content-type matched format.
Merge pull request #285 from dblock/rip-error-format

Removed error_format, will match the request content-type matched format.
Update CHANGELOG.markdown
s/contnet/content/g
Merge pull request #287 from bobthecow/patch-1

s/contnet/content/g
Fix tiny typo in README.markdown
Merge pull request #288 from wakeless/patch-1

Fix tiny typo in README.markdown
Added missing test for xml error formatter
Removed unused 'status' argument to format_message
Updated param name in comment to match code
Removed unused variable 'scope'
A bunch of tiny code cleanups
Corrected spelling error in README
default xml error formatter root should be error instead of hash
use old style hash
Merge pull request #289 from evjan/master

Added missing test and cleaned some code
add specs and changelog entry
use .to_s method in spec, to pass on all ruby platforms
add real xml specs and builder as dependency for this tests