FIX: Confusion between HTTP errors 403 & 401.

As stated in RFC 2616, when access is "forbidden" (403):

    Authorization will not help and the request SHOULD NOT be repeated.
FIX: Exception on resource creation.

Regression caused by 513d403812444e49a18e52139c3c8bf1f15ff972.
FIX: Simplified configuration by using defaults.

Now:
- `final` is always enabled,
- `method` must be used instead of `context.requestIn.method`,
- `path` must be used instead of `url.parse(context.requestIn.url).path`.

Rules management has been highly refactored.
FIX: Exception when a rule is applied.

Regression caused by 44534427411bf54e360720f12af9e4a109db22c9.
FIX: Exception when a rule is malformed.

Regression caused by d7ce0483d8640b86b4a91b7fce7f9b90b1acdb6a.