* Added required files from nettle:hpke(npocs) into /lib/nettle/hpke
* Created new files "hpke-gmp.h" and "hpke-gmp.c"
* Replaced "gmp-glue.h" with "hpke-gmp.h"
* Removed unused var 't' hpke-hkdf.c:54
* Resurrected nettle-alloca.h
* Modified hpke-hkdf.c to use "ecc_scalar_set()"
* Modified devel/indent-gnutls to ignore nettle/hpke

Signed-off-by: Ajit Singh <ajeetsinghchahar2@gmail.com>