This changes how the --source driver argument works.  I split this into four arguments:

-S : Specifies a command file which will get sourced after the ~/.lldbinit but before file arguments are processed
-O : Specifies a single (one-line) command that will get ditto

and

-s : Specifies a command file which will get sourced after `pwd`/.lldbinit
-o : Specifies a command file which ditto

I also changed it so that by default these sourced commands will print their command result, but there's a
-q option to change that if you wish.