Remove pyqi driver config file

Short story: no more pyqi config file.

Longer story:

Easiest way is to describe with an example (let's use the biom-format project):

Instead of using a config file at ~/.pyqi/biom to point to the command config directory, you can run the following command:

```
pyqi --driver-name biom --command-config-module biom.interfaces.optparse.config -- add_metadata -i in.biom -o out.biom -m md.txt
```

The driver also supports a ```--verbose``` flag to obtain slightly more output if errors occur in loading stuff.

In the biom-format project, we can create a ```biom``` executable that is just a shell script with the following lines:

```
#!/bin/sh
exec pyqi --driver-name biom --command-config-module biom.interfaces.optparse.config -- "$@"
```

and then run a command like so:

```
biom add_metadata -i in.biom -o out.biom -m md.txt
```

```%prog```, help, and bash tab completion seem to all be working. This was pretty rushed, so please let me know of any issues.