Moved Strassen algorithm into playground, does not get called from blas::mm(…) any more.
New function: blas::extensions::mm_strassen(transA, transB, alpha, A, B, beta, C)
Added interface to csymv and zsymv provided by lapack
Completed implementation of cxxblas::trcopy
(1) Added functionality of axpby
(a) cxxblas interface
    - generic functions axpby (and acxpby) first scales y and then calls axpy (acxpy)
    - Intel MKL, ATLAS and VecLib provide optimized functions for axpby, which get called if possible
    - optimized functions with SSE/AVX available in playground
(b) FLENS-BLAS
    - y = alpha*op(x) and B = alpha*op(A) call axpby or acxpby
    - y = beta*y + alpha*op(x) and B = beta*B + alpha*op(A) also calls axpby or acxpby

(2) Automatic Macro definition
    - WITH_MKLBLAS defines USE_CXXLAPACK and HAVE_FFTW
    - WITH_VECLIB defines USE_CXXLAPACK
Added overloaded operators += and -= for TrMatrix
Added missing cxxblas functions axpby and acxpby [tinylevel1]
Extended BLAS Level 2 & 3 for sparse matrices
- added syccsmv and level 3 functions
- generic implementation of sv and sm still missing
- Intel MKL provides sparse BLAS level 2 and 3 functions, which get called if possible
- Added triangular matrix types for CCS and CRS Storage
Added Interfaces and examples for sparse matrix solvers:
- SuperLU
- SuiteSparse
- Intel MKL DSS
Added function to determine cache sizes automatically on Linux and MAC