Move logging out of BDM attach method

We will want to call attach in code paths other than booting an instance
(attaching a volume to a running instance for example). This patch
moves the boot specific log message out of the attach method.

Change-Id: Id70d3cabdd118ee1879d7b593765a5034a7ec88e
Add ESX quality warning

In line with the other drivers we've been marking as untested,
this patch marks the ESX driver as "not tested" in the logs to
alert admins to the fact. The VCenter driver is being tested
with minesweeper, and thus does not emit a similar message on
startup.

Change-Id: I9217bab01761f68b716cdce3b21c2653abd9afa1
Rename API schema modules with removing "_schema"

The paths of API schema modules include "/schemas" and they show
API schema clearly. It is not necessary to include "_schema" in
module names. This patch renames the modules with removing "_schema"
from module names.

@validaiton.schema() takes 1 parameter, so calling it by name
is excessive. Then, this patch removes the specified argument.

By applying these changes, we can specify API schema module in one
line with @validation.schema().

Partially implements blueprint nova-api-validation-fw

Change-Id: Ia646e1c2466fa0a1418f757a48d2e6b4f84f7c98
Merge "Rename API schema modules with removing "_schema""
Merge "Move logging out of BDM attach method"
Merge "Add ESX quality warning"