Target v1.1.9
Merge branch 'release/staging' into develop

Conflicts:
	package.json
More ignores
Handle SQL API errors by logging them and requesting NO cache

SQL api is used to determine the list of source tables affected
by a query. Before this commit, the X-Cache-Channel header set
on sql api error was an arbitrary 'table' string, now the header
is omitted, the error logged and Cache-Control and Pragma headers
are sent as an attempt to request no caching.

The code includes test for this mechanism.
Update NEWS
Draft test for X-Cache-Channel in multilayer response

The test is disabled because it fails
Absence of X-Cache-Channel will be enough for Varnish to skip caching

Do not override Cache-Control in this case, which means let the
clients or geographical proxies cache the response with usual TTL.
Run multilayer test as part of "make check"
Fix X-Cache-Channel for multilayer (by token) responses

Required upgrading Windshaft to 0.9.2
Includes testcases
Add last_modified field to POST layergroup response (#72)

Includes testcases
Cleanup, handle error in req2param on flushCache
Deprecate USR1 signal handling, add USR2 with same semantic

Closes #71
Write a deprecation warning when handling SIGUSR1 (#71)
fixed last_update in laytergroup response
Fix support for ampersend characters in CartoCSS

Required upgrading grainstore dependency to 0.12.2
Add support for LZMA compressed GET parameters

You can now replace the whole query string with a single `lzma`
parameter having as value an hex encoded LZMA compressed version
of the whole query string as a JSON object.
Add test showing use of mapnik subtitution tokens in multilayer config
Upgrade Windshaft to 0.10.0, changing multilayer interface

WARNING: starting from this commit the grid fetching route changed
         to NOT include layer name nor interactivity (which is now
         specified solely as part of layergroup configuration)

Target 1.2.0 release
Require interactivity param in single-layer grid fetching request

Closes #69
Target v1.2.1