Generate FLIRT signature file

 Action    name: makesig:create_signature
 

This command generate a FLIRT signature file. A function is eligible when then name don't start with "sub_".

 File: Pathname for the signature file
 Library name: identifier, shown in the description of Signature

 Collect functions
  - All: Generate signature for all functions in the idb that are eligible
  - Selected: Generate a signature only for the selection in Functions

 Collisions
  - Ignore: don't add collision FLIRT signature
            will delete the Exclusion file if it exists
  - Deal with manually: if there is collisions, a window will open to manage
                        the collisions

Two or three files are generated:

 - Signature file: The output file
 - Pattern file:   Filename is Signature filename with extension replaced
                   with "pat"
 - Exclusion File: Filename with extension replaced by "exc"
                   Only present if you want to deal with collision and there
                   is any.

The last two files can be deleted once the signature file is generated.