* configure.ac: Use assembler file arcfour-crypt.asm if available.

* arcfour.c (arcfour_crypt): Moved function too...
* arcfour-crypt.c (arcfour_crypt): New file.

Rev: src/nettle/Makefile.am:1.69
Rev: src/nettle/arcfour-crypt.c:1.1
Rev: src/nettle/arcfour.c:1.5
Rev: src/nettle/configure.ac:1.29