Fixes newly-vended laptops opening windows and giving close messages

As in title.

Before this commit (current behaviour):
* Vend laptop from vendor, swiping ID.
* Laptop is spawned, defaults to open.
* Laptop's `New()` causes program to execute, opening the "Welcome to NTOS" window.
* Vendor calls `verb/close_computer()` on laptop, giving a "You close the laptop" output.
* Window remains open, though the laptop is closed.

After this commit:
* Vend laptop from vendor, swiping ID.
* Laptop is spawned, defaults to open.
* Laptop's `New()` does not execute a program.
* Vendor calls `proc/close_laptop()` on laptop, giving no output.

`verb/close_computer()` has been modified slightly to perform the relevant checks on `usr` (adjacency, non-deadness etc.), then call `proc/close_laptop()`, which performs the relevant checks on the laptop.