Correct sample config default log levels

The documentation of the default_log_levels default value in the
sample keystone.conf file was out of date. The default value has
been updated to the current value in keystone.openstack.common.log.

Change-Id: I3edf2d5375413250de41f8cebb98a826dc5df8ce
Update the default_log_levels defaults

The default for default_log_levels didn't set the log levels
for some packages that Keystone uses (for example, dogpile). This
caused the server to output a lot of extra logs when debug=True
is used.

You can get the debug output for dogpile and routes by setting
default_log_levels explicitly in your keystone.conf file.

Change-Id: Ib797fa7b98f0e501047b72b094d07ad204385cc6
Related-bug: #1245629
Closes-Bug: #1269987
Implement list limiting support in driver backends

Provides an optional limit to the number of rows that will be
returned by a backend from a list_{entity} call.  The limit is specified
in the configuration file, and allows for an overall general limit as
well as an individual limit for a given driver.  By default, there is
no limit.

Limitations:
    - The list limit is not yet handled by LDAP, rather this remains
      implemented in the final wrap collection - a subsequent patch
      will provide the support in the LDAP drivers

Implements bp list-limiting

Change-Id: I7ca76a8da4260242e578c44103b26257f7e2a5d5
Adds rule processing for mapping

Adds a function to compare mapping reference rules to
incoming assertion headers, returns a set of identity
values.

bp mapping-distributed-admin

Change-Id: If11539fb66dfeb778755e4f5d2ba8efb2fab522c
Merge "Adds rule processing for mapping"
Merge "Correct sample config default log levels"
Merge "Update the default_log_levels defaults"
Merge "Implement list limiting support in driver backends"