Get rid of "2 character hack" in multiThreadCommands

[mnwhite]

In #852 Mridul got rid of a usage of exec, but maintained the style that the arguments to multiThreadCommands and multiThreadCommandsFake include parentheses. He did this by stripping off the final two characters from each element in the string.

Instead, we should change the argument style to not include those parentheses by removing them in all instances where they're used, and then deleting the [:-2] from these functions.