Merge pull request #336 from ufo-kit/improve-scan

Improve scan
Add sample changer base class
Add dummy sample changer
Add sample changer test
Add sample changer to docs
fixed units checking for @expects
don't check function arguments as long it's not Numeric instance or Device class
Merge pull request #337 from ufo-kit/add-samplechanger

Add samplechanger
Generalize base detector
Adjust dummy detector for generalized base
Merge pull request #221 from ufo-kit/add-elya-detector-system

Prepare for Elya detector
Merge pull request #319 from ufo-kit/expects

Fix #308: Expects decorator does work with code_of
Add base gripper
Add dummy gripper
Add gripper test
Add grippers to docs
Support asynchronous grabbing by grab_async

fixes #305
Add grab_async test
Merge pull request #343 from ufo-kit/grab-async

Support asynchronous grab for long exposure times
Merge pull request #342 from ufo-kit/add-gripper

Add gripper
Revert "Don't disaply empty windows on ctrl-c by pyplot"

This reverts commit 1a8d23b82b35564bcc1d36ad21fd527e8a6bfec8.