Merge branch 'cloudendpoints:master' into master

fix JacksonResourceSchemaProvider to work with jackson > 2.11.x (fix …

…from cloudendpoints#207)

increase read timeout for larger discovery docs

increase read timeout for larger discovery docs

increase read timeout for larger discovery docs

v2.2.1 includes minor fixes

* inline files.write() in GenApiConfigAction
* improve Swagger generation
* convert standard logging to use flogger

v2.2.0 includes some major functionality changes

* improved OAuth2 scope handling
* some refactors to allow advanced users to extend/override default
  Endpoints behavior (auth code, serialization)
* greatly improved resource usage by serializing the response object
  to stream instead of storing the whole result in memory first
* improved OpenAPI compatibility
* google-http-client is bumped to 1.25.0 to address vulnerabilities
* deprecate JsonMap schema generation in favor of using
  additionalProperties, the standard for JSON schema. This feature can
  be turned off by setting environment variable
  ENDPOINTS_MAP_FORCE_JSON_MAP_SCHEMA to true, or by setting the
  system property endpoints.mapSchema.forceJsonMapSchema to true. This
  new functionality can be further configured (see
  EndpointsFlag.java).
* add option to disable Jackson annotation integration. Set
  environment variable ENDPOINTS_JSON_USE_JACKSON_ANNOTATIONS to false
  or system property endpoints.json.useJacksonAnnotations to false.
* support multipart/form-data requests for requests that are all named
  parameters

v2.1.2 fixes a few issues

* print full exception info on tool failure
* OpenAPI spec generation now checks that -o argument isn't a
  directory
* update Jackson dependency to 2.9.6 to address CVE-2017-7525

v2.1.1 fixes two minor issues

* OpenAPI spec generation now sets a string type for enums
* a printStackTrace() call has been changed to use a java.util logger

v2.1.0 fixes some compatibility issues

* underscores are allowed in API names in very old versions of Endpoints
  v1, so we allow them without adding them to the documentation.
* required parameters now have null checking added to them.