EMAIL/EDIT: Improve argument passing

[bobbimanners]

Right now, EDIT.SYSTEM assumes that if it was called with any arguments it was by EMAIL.SYSTEM. This is not necessarily the case. Also, in this case it always asks whether to attach files, and if so calls ATTACHER.SYSTEM.

Add additional parameters to make this explicit. Perhaps:

• EDIT.SYSTEM path/to/filename - Just open the file. Quit to ProDOS.
• EDIT.SYSTEM emailrecv path/to/filename - Open the file and quit to EMAIL.SYSTEM
• EDIT.SYSTEM emailsend path/to/filename - Open the file and ask about attachments on quitting. Call either ATTACHER.SYSTEM or EMAIL.SYSTEM

[bobbimanners]

I beefed up the argument passing when EMAIL.SYSTEM calls EDIT.SYSTEM. It is now as follows:

• EDIT.SYSTEM - Launch editor with no file, quit to ProDOS.
• EDIT.SYSTEM foo.txt - Launch editor and open `foo.txt, quit to ProDOS.
• EDIT.SYSTEM -reademail foo.txt - Launch editor and open foo.txt, quit to EMAIL.SYSTEM`.
• EDIT.SYSTEM -compose foo.txt - Launch editor and open foo.txt. On quit ask whether to add attachments and if so launch ATTACHER.SYSTEM, otherwise quit to EMAIL.SYSTEM.