using small dataset
fix the memory leak issue
add the base class for KL methods
Merge pull request #2292 from lambday/develop

added proper lapack check to address issue #2291
Merge pull request #2286 from yorkerlin/variational-example

variational_approx_example using small dataset (for memory check)
Merge pull request #2287 from yorkerlin/develop

The base KL method class
prevent failure in class_list.cpp when LAPACK is not present