Merge pull request #1865 from iglesias/develop

Typo fixes and other minor changes in multiclass KNN notebook.
Fixed MALSAR clustered LR fallback (affects #1360)
Fix issue #1869
Add coveralls badge to README.md
remove coverage stats of examples, tests, benchmark, cmake
Fix erronous function call introduced in the previous commit
Revert previous try for fixing #1869
change back release_weight_vectors to SG_FREE