Auto place

[huwshimi]

Added a button to auto place all unplaced units onto new machines.

[huwshimi]

QA:

• open the machine view
• there should be a message "You have placed all of your units"
• add some units to the canvas
• the machine view should now list the unplaced units and should have a new button and message: "Auto place or manually place" (see: https://www.dropbox.com/sh/7ha5rmvu2prfioy/AACuSt7AaYCH735IgvprGC5Sa#lh:null-MV-no-more-menu-08.png)
• click "Auto place"
• the unplaced units should return to "You have placed all of your units" and there should be new machines for each unplaced unit

[hatched]

This can be shortened to state = (show) ? 'placed' : 'units';

[kadams54]

👍 QA is OK, with the one tweak @hatched mentioned above.

[jujugui]

Test FAILed.
Refer to this link for build results: http://ci.jujugui.org:8080/job/juju-gui/1540/

[jujugui]

Test PASSed.
Refer to this link for build results: http://ci.jujugui.org:8080/job/juju-gui/1546/

[huwshimi]

Thanks @hatched and @kadams54

[jujugui]

Status: merge request accepted. Url: http://ci.jujugui.org:8080/job/juju-gui-merge