Merge pull request #1893 from minrk/compositeerr Update Parallel Magics and Exception Display Based on feedback from @fperez, a few small changes to parallel exception handling and magics: Exception changes: * apply_requests trigger showtraceback machinery, so apply errors are as pretty as execute ones * InteractiveShell.showtraceback handles RemoteErrors, so it only draws the remote traceback, rather than the unhelpful local one. Magics changes: * removed parallelmagic extension * creating a Client *implies* activate of a lazily-evaluated directview on all engines * can activate Magics on multiple views with different suffixes: ```python eall = rc.activate('all', 'all') e0 = rc.activate(0, '0') %pxall a=5 %px0 print a ``` * add %pxconfig magic for changing default block/targets for a collection of magics * add targets arg to %%px cell magic * %result renamed to %pxresult for consistency (%result kept for bw compat) * %pxresult now only draws most recent result, but accepts all the output-formatting args of %%px * add --out arg to %%px for storing the AsyncResult object in the user_ns * changed %px to not be verbose by default, and added verbosity control to %pxconfig.