Different simple fixes:
* Getting imports right (mixed up libp3bm.h and libppbm.h)
* Not defining BufSize in every so solver by defining it extern in libbmrm.h
* Correcting wrong initialization of beta[i+1] in libppbm.cpp
* Termination criteria: exit loop if next iteration would exceed CP buffer
Using gtest to run the same tests for all solvers.
* Outsourced dummy data to helper functions create_test_labels() and create_test_features().
PCA eigen-ized
SVD based PCA added
code cleaned
failing LMNN unit-test : test_pca_init changed
brief documentation updated + apply_to_feature_vector updated
PCA code cleanup
updating revision of data submodule
update data submodule : lmnn_modular changed
HAVE_LAPACK to HAVE_EIGEN3 and header changes
drop the package name so we will have names modshogun.CLASS with swig 3.0
Merge pull request #1915 from mazumdarparijat/pca

PCA eigen-ized
hsic bugfix and interface changes
HAVE_EIGEN3 guard changes to counter make error w/o eigen3
removed lapack guard from LMNN files
very minor changes in NEWS
Merge pull request #1926 from lambday/feature/hsic_bugfix

hsic bugfix and interface changes
Merge pull request #1922 from votjakovr/feature/fix_parameter_hashing

Fix parameter hashing framework
changed ERROR to WARNING to tackle travis/buildbot failure when mldata is in flaky state