Fix hoqide

Bas told me that hoqide said

```
Error during initialization:
Error: File not found on loadpath : stmworkertop.cmxs
```

So now we copy the stm directory (which contains stmworkertop), too.

Although I haven't tested this myself (yet), @spitters tells me that it works.  Perhaps whoever acks this should make sure that this exact commit works by running something like
```bash
git clone https://github.com/JasonGross/HoTT.git --branch fix-hoqide HoTT-test-hoqide
cd HoTT-test-hoqide
git checkout fix-hoqide
./autogen.sh
./configure
make
./hoqide
```