This patch introduces two new keys 'g' and 'G' that helps to navigate to the
top and bottom of the file/hunk/line respectively. This is inline with the shortcuts
used in man, less, more and such tools that makes it convenient to navigate
'g' or HOME navigates to the top most file in the ncurses window.
'G' or END navigates to the bottom most file/hunk/line depending on the whether
the fold is active or not.
If the bottom most file is folded, it navigates to that file and stops there.
If the bottom most file is unfolded, it navigates to the bottom most hunk in
that file and stops there. If the bottom most hunk is unfolded, it navigates to
the bottom most line in that hunk.