Client:

- Added field validation to structures received from server API
- Completed vmattachsingle (but disabled - only present for testing the route)
- tpledit was removed by mistake in a previous commit: it's back now
- Bumped to version 1.9.3

Server:
- Changed max #cpus from 16 to 32
- Changed min ram from 256MB to 128MB
- Changed min VM name length from 4 to 1 char
- Bumped to version 1.9.3
- Completed /vms/{id}/attach route