Have CommandObjectCommandsAddRegex inherit from IOHandlerDelegateMultiline so...

Have CommandObjectCommandsAddRegex inherit from IOHandlerDelegateMultiline so it will not immediately terminate after the first regular expression in "command regex <name>" commands.

Fixed the prompt to not include non-printable characters as it was hosing up the prompt when you ran "command regex foo" and entered multi-line editing mode.

Fixed error strings to include more complete descriptions when bad regular expressions are entered.

Removed the old IOHandlerLinesUpdated function as it is no longer needed (inheriting from IOHandlerDelegateMultiline takes care of what this function used to do).

llvm-svn: 222207