Prepare for 1.8.5
Properly prefix statsd labels for all endpoints

CDB-1861 #resolve
Will be 100% complete with update of Windshaft to 0.19.3+
Raise 403 forbidden on missing requested signature

Closes #170
Includes testcase
Fix error message on missing requested signature

We don't really distinguish between missing or non-authorizing
signature. And that's fine. See #170
Do not cache map creation responses

Closes #176
CDB-1908 #resolve
CDB-1901 #resolve

Includes testcase
Do not log an error on GET /

Closes #177
Use 403 for forbidden, not 401

Includes upgrade of windshaft to 0.19.3
Includes upgrade of redis-mpool to 0.0.4
Do not UNWATCH on every redis client release

Closes #161
Include API docs, moved from wiki

Closes #164
Add "dnsCache" statsd setting in the example configs
It is "cacheDns", not "dnsCache"

See https://github.com/sivy/node-statsd/issues/38
Do not send duplicated stats on template instanciation

Closes #179
Cleanly catch exceptions from sendResponse

Closes #178
Upgrade windshaft to 0.19.3, fixing crash on dns error

Closes #180
added serverMetadata option for layer group, close #182 CDB-1940
added cdn_url option
fix formating
Merge branch 'server_metadata'
Retarget to 1.9.0
More format changes