#73 Provide THE equivalent for push

[Shmuel (Seymour J.) Metz]

It is common for REXX script on CMS and TSO to use push to cause a command to be executed after the script completes. *BSD, DOS,, Linux, OS/2 and windows have no facility for maintaining a command stack, and the stack in Rexx is strictly a Rexx construct. This causes problems when porting Rexx code from the mainframe, including XEDIT macros. It would be helpful if THE had a mechanism for a macro to pass back commands, or at least a single command, to be executed after the macro terminates.