Remove old information about  `rlcompleter.py`, obsolete since new shell

```
Since we moved from IronTextBox to the PythonConsoleControl from the ironlabs 
project, the information about autocompletion is outdated. This needs to be 
revisited and fixed in documentation (and in the default InitScript)

```

Original issue reported on code.google.com by `dthomas.ch` on 13 Nov 2011 at 11:02
