Found in master:4bc3f0994e68b3302a0523a3156dd0dca0cac7a0

Steps to reproduce:

1. Create a project with Toaster in managed mode
2. Click the 'change' icon next to the machine name
3. Type some gibberish (i.e. do not select one of the values provided by the type ahead)
4. Click the 'save' button

The machine value reverts to the previous one, instead of taking the value you typed in step 3. This also means that, for a local project, where we don't have any information about machines, it is impossible to change the machine value.

Machines are like build targets: we can never be sure that Toaster knows of all valid options. Therefore, we need to allow free text entry.