a: edit: Crashes on '^' or '$'

[jubei85]

Win7/64 go 1.9 crashed if input commands: 1,$s, 1,$p and etc...

[as]

There are two separate issues here:

• The lack of the print command 'p'
• The crash that occurs upon a ^ or $ symbol

Because the latter causes the crash, we will address that issue here. A separate issue will be created for missing p.

[as]

Those specific constructions should work for the most part. Added p and s, but the edit program is overdue for refactoring.

Some tests
Edit ,x,func.+,=
Edit 2,$p
Edit ^,10,p