Only require the necessary bits of ActiveSupport

Addresses issue #353 -- Log formats silently changed between versions

The default log format changes after `require 'active_support/core_ext/logger'`, and
of course `require active_support/all` brings in everything including loggers.

To change the format back to the default for a particular logger, you can
use `my_logger = Logger::Formatter.new`.
Merge branch 'issue353-log-format-change' of github.com:rhunter/grape
Merged #354 and added a spec.
Fix: mount Grape middleware behind Error to allow error trapping, introduced in 48d05b50ec5351fdfde6a68b37d69c58a73c2381.
Fix: undefined method call for nil:NilClass for an API implementation without a block, now returs an empty string.
Preparing for 0.4.0 release.
Bump version to 0.4.1.
Update CHANGELOG.md
Update README.md, spec/request -> spec/requests
Merge pull request #372 from Radagaisus/patch-1

Update README.md, spec/request -> spec/requests
requires active_support/core_ext/objects/conversions ,since there's a usage of to_xml

this can be produces by run `s spec/grape/api_spec.rb:1841`.
when using rake, there'll be no errors, I think maybe some other dependency requires it earlier
Merge pull request #374 from niedhui/quick_fix

requires active_support/core_ext/objects/conversions
Fix #375: throwing an :error inside a middleware doesn't respect the format setting. The api.format environment has not been set, yet.
Adds API.route_param for quick declaration of route parameters.
Preparing for 0.4.1 release.
Bump version to 0.4.2.
Only catch formatter errors in formatter middleware
Add spec for formatter middleware error handling
Catch in both tests to make meaning clearer
Update CHANGELOG