Add CouchError to wrap REST errors in Error object

closes #216
closes #213
[api] Allow disabling of conflict-overwrite via options.forceSave
Merge pull request #241 from sreuter/master

[api] Allow disabling of conflict-overwrite via options.forceSave
[dist] Updated dependencies.
[dist] Version bump. 0.6.7
Merge pull request #235 from holic/master

Add CouchError to wrap REST errors in Error object
[test] Added basic tests for CouchError
Copy headers to error object explicitly.
The way that cradle/response.extend works means the properties don't enumerate
Merge pull request #245 from davedoesdev/fix-errors-and-tests

Copy headers to error object explicitly.
README.md typos
Merge pull request #254 from Cecchi/patch-1

README.md typos
Fix validation_doc_update example
Merge pull request #262 from kxepal/patch-1

Fix validation example