Avoid Quartz lazyloader `from Quartz import *` bug

Change `from Quartz import *` to the fast `import Quartz`, and update
all references to Quartz objects to be explicit.

pyobjc's lazyloader makes the form `from ... import *` very slow. This
can make importing pymouse extremely slow on OS X due to its use of
from Quartz import *.

See the issue discussion on the pyobjc project:

https://bitbucket.org/ronaldoussoren/pyobjc/issue/2/faster-metadata-support

From that thread on 2013-07-16:

> If you are only using framework wrappers: make sure you do not use "from
> Foundation import ", use "import Foundation" or "from Foundation import
> NSObject" instead. Someone recently noticed that the "from ... import "
> form is currently much slower than it used to be, due to the way the
> PyObjC lazy loader is implemented. I'm working on a fix for that, but
> even with the fix explicit imports will be better because they perform
> less form (because explicit imports don't have to resolve the symbols
> you don't use).

pymouse has this exact problem due to its use of `from Quartz import *`:

$ time python -m pymouse
...

real	0m14.961s
user	0m14.275s
sys	0m0.164s

Changing to just `import Quartz` solves the extremely long hang at
import time problem; after this commit:

$ time python -m pymouse
...

real	0m0.495s
user	0m0.381s
sys	0m0.092s
Fix Quartz import style speed bug in pykeyboard

Change from `from Quartz import *` to `import Quartz` and upate Quartz
object references. See previous commit fixing the same bug for pymouse.
Add test for import time of pymouse and pykeyboard
Mark import time tests as skipped by default