moved BLAS/LAPACK detection scripts to the main repository. Give preference to the external BLAS over OpenCV's gemm, which improves performance of dnn module by a lot

fixed some compile warnings in dnn & protobuf; improved convolution layer performance when blas is not available by parallelizing gemmCPU() function in dnn

Also, small fix inside inside Python types conversion was added

Moving more Caffe loaders to sparate file