Refs #54. Added AMD Bulldozer x86_64 dgemm kernel developed by Werner Saar <wernsaar at googlemail.com>

Based on the dgemm kernel for AMD Barcelona, he used AVX and FMA4 instructions.
Thank Werner Saar!

kernel/x86_64/KERNEL.BULLDOZER

@@ -10,7 +10,7 @@ SGEMMINCOPYOBJ =  sgemm_incopy$(TSUFFIX).$(SUFFIX)
 SGEMMITCOPYOBJ =  sgemm_itcopy$(TSUFFIX).$(SUFFIX) 
 SGEMMONCOPYOBJ =  sgemm_oncopy$(TSUFFIX).$(SUFFIX)
 SGEMMOTCOPYOBJ =  sgemm_otcopy$(TSUFFIX).$(SUFFIX)
-DGEMMKERNEL    =  gemm_kernel_4x4_barcelona.S
+DGEMMKERNEL    =  dgemm_kernel_4x4_bulldozer.S
 DGEMMINCOPY    =
 DGEMMITCOPY    =
 DGEMMONCOPY    =  gemm_ncopy_4_opteron.S