Put idris-process into comint
Run idris-process in comint

This does the following:

1. Put the idris process buffer in Comint mode
2. Arrange for the port number to not show up
3. Pop to the buffer when something is output to it, as it will
otherwise cause things to block from time to time
Fix warning
Merge pull request #243 from david-christiansen/issue/21

Make :x and type providers work conveniently