Shrink favicon.ico to make the bits faster

Following the tips at http://zoompf.com/blog/2012/04/instagram-and-optimizing-favicons,
with help from https://tinypng.com/, http://pngquant.org/, and http://www.nongnu.org/icoutils/
the favicon has been shrunk from a 32x32 px 8-bit ico to a 16x16 4-bit ico, thus
shaving off nearly 60% of the bits (58.49%, to be exact), going from 766 bytes to 318.