fz[?][name] add named flag zone -name to delete. see fz?[name]

Usage: f [?|-name| name] [@addr] # Manage flagzones

• fz math add new flagzone named 'math'
• fz-math remove the math flagzone
• fz-* remove all flagzones
• fz. show around flagzone context
• fz: show what's in scr.flagzone for visual
• fz* dump into r2 commands, for projects