Compile flags for hmmer

["Nelson A. de Oliveira" <naoliv@gmail.com>]

Hi!

Still about the compiler flags for hmmer (#594860), on i386 [1] and
kfreebsd-i386 [2] it's being used the SSE implementation (compiled
with -msse2).

While it's almost sure that people who use hmmer have processors >=
Pentium 4 and Athlon 64, there is still a small probability that some
users won't be able to run hmmer on i386 and kfreebsd-i386.

[1] https://buildd.debian.org/fetch.cgi?pkg=hmmer;ver=3.0-2;arch=i386;stamp=1283105357
[2] https://buildd.debian.org/fetch.cgi?pkg=hmmer;ver=3.0-2;arch=kfreebsd-i386;stamp=1283105721

While the generated code is faster with SSE, Debian still supports
older Pentiums and 486s [3].

[3]  http://www.debian.org/releases/testing/i386/ch02s01.html.en#id2585277

Will we let it being compiled with for processors that support SSE only?

Best regards,
Nelson