Add a db check for CHARSET=utf8

This is to prevent confusing migration errors caused by
tables having mixed character sets like latin1.

Change-Id: I19da8d5e2d972c78d0f9fb4325445f538ed35600
Closes-bug: #1261605
Use entry points to discover options in libraries

When generating the sample configuration file, we want to include
options defined in libraries used by the application (especially
oslo libraries). Add a section to the sample generator to look
at entry points in the 'oslo.config.opts' namespace and include
their return values in the output.

Implements: blueprint improve-config-discovery-for-docs
Related-Bug: #1241566

Change-Id: I635cd8e60ca687851c9dd891667ecc2ca3e8720c
lockutils: remove local usage

This doesn't seem like it's used by anything any more, so let's just
remove this local usage altogether. This also drops the lock check from
RPC, which shouldn't be a problem considering that this library is
already deprecated altogether.

Change-Id: I87ff0338adcfa092fd21acad5cf41d5746be1efe
lockutils: do not grab the lock in creators

The functions used to create the lock should not grab it, as it is not
their roles to do so. Instead, the lock is acquired in the decorator
using these functions.

Change-Id: Ia6d550869ae1c60883658af1c385d49728b6cd60
lockutils: expand add_prefix

There is no need to build a function closure each time we run through
this code. It is more effective to expand the code right away, so let's
do that.

Change-Id: I13174727e88bf5aa86659b6271d13ebcddc7708c
lockutils: remove lock_path parameter

This remove the parameter lock_path so the configured lock_path is
always used instead. There's only a few places where this is used in
OpenStack, and it's not heavily justified to have it even in this
places.

This is needed to simplify the interface toward moving to IPC locking
mechanism. With such a locking mechanism in place, the lock_path
parameter has absolutely no sense. So isolating this to make it only
relevant to some part of the driver and not in the public interface
makes more sense.

Change-Id: I72bd683209090ae6e3911a709e4d213879508aca
Blueprint: lockutils-posix-ipc
lockutils: move directory creation in lock class

We are going to implement a lock mechanism that does not rely on file
path at all, so there's no need to create such a hierarchy in advance.
Let's do that job in the class actually implementing the external lock
mechanism.

Change-Id: Ibd55ef6ee517f615dd6b398ebe72d1c6552f4675
Blueprint: lockutils-posix-ipc
Adding cache entry to Maintainers file

Adding the cache entry to the MAINTAINERS file

Change-Id: I0792c87300bdf28525db30183acbe06870254bad
Merge "Use entry points to discover options in libraries"
Merge "Add a db check for CHARSET=utf8"
Merge "Adding cache entry to Maintainers file"
Merge "lockutils: do not grab the lock in creators"
Merge "lockutils: expand add_prefix"
Merge "lockutils: remove lock_path parameter"
Merge "lockutils: move directory creation in lock class"