Behavior of M doesn't match Vim's

[Chun-Yu Shei]

Hi,

I was actually going to report a couple of other bugs/issues, but it 
looks like they've recently been fixed (lack of `. and dw sometimes 
deleting newline). :)  So, the only small issue left for me is that the 
M key doesn't behave the same as Vim's when you don't have a full page 
of text on screen.  Vim will move the cursor to the middle of the actual 
text, whereas Evil always tries to move it to the exact vertical center 
of the window.  In extreme cases, when the amount of text is less than 
1/2 screen, M and L do the same thing in Evil.  Is this something that 
can easily be fixed?

Thanks for all the awesome work!

Chun-Yu