String kernel fixes

- add reasonable sqrtdiag normalizer to LI kernel
- add convenience constructor to the oligo kernel
- add slow compute function back to oligo kernel
- use SGVector instead of ptr & len
Bugfix for SLIK kernel

- remove left over init code in compute function of SLIK kernel
- this init code caused an unstable pyramid array, making
the kernel fail when #threads > 1
fix data generator for kernel integration tests
suck in new integration test data
1e-9 accuracy for LA kernel
disable broken HMM in tests for now
really blacklist HMM
add blacklist support to all interfaces' integration tests
blacklist failing SGD/SVMLin tests
added log-det method for sparse matrices in CStatistics