[NEW]: frame-selection commands: frame, up, down, select-frame, silently-up, silently-down

[GitMensch]

Which command do you need
frame, up, down and their silent pendants, see GDB documentation
Note that frame and select-frame take a "frame-selection-spec", which is "no input", "a number", or a function-specifier (function-name or address; those are also possible in bp-related), up and down + silent variants take an optional number

Describe the rendering you'd like
Just as any other command

Examples & tests

frame
bt
f 3
up
silently-down 2

[pirpyn]

Will try to do that on the next few days. Needs some refactoring

[pirpyn]