general.debugcontext: filter out cmdlist and arglist
Core/Applets: log applet start/stop and duration
Core/ProcessManager: fix potential race-condition with $context object
Core/Interpreter:
* expand pronouns before command-substitution
* attempt to find current channel's factoid instance for metadata
* remove duplication of command history in command-substition
* terminate pipe/substitution processing when protecting self
Core/Factoids: limit -url contents to 250kb