Anotation support as "decompiler list"

[trufae]

Latest r2 from git supports adding function annotations with the ano command.

[0x00000000]> ano?
Usage: ano  [*] # function anotations
| ano   show or edit annotations for the current function
| anoe  edit annotation
| anos  show annotation
| anol  show first line of function annotation if any
[0x00000000]>

thing is that iaito should add a button to edit the annotations, with a textarea widget or whatever inside the same decompiler window. not just display it.

[trufae]

Initial implementation: #190

TODO:

• add button to edit those anotations
• check for r2 version to be >= 595