fix issue #1611
cleanup svm_binary_classification.ipynb
Dump gmock version to 1.7.0
Fix typo in Serialization_unittest.cc
fix issue #1677: use mathjax in doxygen for displaying mathematical formulas
Add valgrind suppression file when running ctest memcheck
add strange leaking errors of libxml2 to the suppression file
add randomized unit-tests for IO, increase precision for ASCII writers
fix latex error in doxygen
Merge pull request #1679 from gsomix/feature/protobuf

Unit-tests for IO
Fix leaking classes related issue #1477
Revert changes in VwRegressor.cpp
fix a small memleak in SGObject.ref_unref unit test
Fix typo in tests/integration/python_modular/CMakeLists.txt
this should fix issue #1661
reduce number of x-validation repeats and number of parameter combinations in grid-search
decreased number of iterations to make test run faster
Merge pull request #1681 from karlnapf/develop

speed ups for tests
removed notebooks since there will be a more complete one soon