erasure-code: remove jerasure version 1

http://tracker.ceph.com/issues/7599 refs #7599

Signed-off-by: Loic Dachary <loic@dachary.org>
erasure-code: use jerasure as submodules

Now that there is a git repository to refer to, it will be good for
maintenance. Pin the version to stable branches.

http://tracker.ceph.com/issues/7599 refs #7599

Signed-off-by: Loic Dachary <loic@dachary.org>
autotools: set SIMD_FLAGS with SSE flags

As well as compiler options.

Signed-off-by: Loic Dachary <loic@dachary.org>
erasure-code: upgrade to jerasure version 2

http://tracker.ceph.com/issues/7599 refs #7599

Signed-off-by: Loic Dachary <loic@dachary.org>
erasure-code: LARGEST_VECTOR_WORDSIZE is always 16

Signed-off-by: Loic Dachary <loic@dachary.org>