Add the ability to view details of a single commit

[fstab50]

$ branchdiff --commit-log

Allows viewing of the various versions of the commits made to a branch and their respective hexadecimal index numbering as show below (image).

Functionality should be added that allows a user to view details of single commit referenced by a hexadecimal index value as follows:

$ branchdiff --commit-log 99abb7a

Output: