v0.1.11

Changes

• switch to Ammonite 1.3.2
• allow interpreters to handle completions and inspections asynchronously (both can be in parallel, and independent of execution requests), and to make them cancellable (attempted when a new completion or inspection request arrives while one is running) - not used by the scala kernel yet
• add helpers to display images (#255 and #258, thanks to @sbrunk)