Revert "autotools: AX_SSE detects the compiler SSE capabilities"

This reverts commit 8c7f6c11d4830a2300e88dc7d27dae4e37d1873c.
Revert "erasure-code: gf-complete detects SSE at runtime"

This reverts commit dbcf4471838fbf5dce2ee06fc73493f513dbf9f0.