User.h and Utils.h should not depend on each other, and instead of name
of default method need to have a function in CUtils, which hashes using
default method (such function is in CUser now)
Previously, a certificate generated with --makepem expired after a year which is
weird and pointless (come on, it's self-signed!).
Signed-off-by: Uli Schlachter <psychon@znc.in>