This picks the following commits (most recent on top):

   e17d874 README: update for the new code base
   d391e62 added 64-bit example/test
   670b5e8 Makefile: support 64-bit option; add div64.c
   c2384cd vsprintf-full: offer 64-bit printing as an option
   220b19e vsprintf-full: simplify a little
   526daa6 vsprintf-full: remove unsed code for %p printing
   1a28825 vsprintf-full: prevent a warning when a pointer is 16 bits

We are using 64-bit prints currently, but wrpc-sw does.

Signed-off-by: Alessandro Rubini <rubini@gnudd.com>