Looking glass narrow view marker wrap around

[gullradriel]

A little update for the Glass:

• allow narrow view as little as 1 MHz
• allow marker to wrap around BOTH corners (and not only on the left side)
• added a define and changed a variable set for clarity

[zxkmm]

I'm not quite familiar with looking glass app, but it looks good and tested good.
I'll approve but if you want others to approve too, feel free to wait or maybe others' can add comments

[gullradriel]

I'm not quite familiar with looking glass app, but it looks good and tested good. I'll approve but if you want others to approve too, feel free to wait or maybe others' can add comments

It's good like it is :-)