Protections numbers meaning in Mach-O

[Mustapha EZZALI]

Describe the bug
I could not find the meaning of protections numbers (0,1,3,5,7) of Mach-O segments in lief documentation.

Environment (please complete the following information):

• System and Version : Ubuntu 16.04 , version = 0.12.3
• Target format : Mach-O

[Romain Thomas]

These numbers represent the classical protection flags:

• X = 1
• W = 2
• R = 4

Thus, 7 is R | W | X