Merge pull request #1309 from ivanov/inoculate-clear-magic Inoculate clearcmd extension into %reset functionality Restored the functionality of this quarantined module, added new tests for it and polished it a bit, and made it available as part of the `%reset` magic. Specifically, the `%clear` completions did not previously advertise the `array` argument option, and `clear in` did not clear `_i`, `_ii`, and `_iii` - both of these are now fixed. Removing the `shadow_compress` and `shadow_nuke` options, as they refer to functionality that does not appear to be used anywhere anymore.