add a new LaplacianInferenceMethodWithLBFGS class, where the Newton method is replaced by the L-BFGS method
modify for Google C++ style
ignore the coding style script
add methods used for LBFGS in CLaplacianInferenceMethodWithLBFGS
complete the implementation of LaplacianInferenceMethodWithLBFGS
we need to set the private data members in LaplacianInferenceMethod to be protected
remove the useless header file
add some comments in CLogitLikelihood
chang the order of matrix multiplication to gain improvement
enable unit test
remove the useless code optimization for matrix mulitiplication
updated the L-BFGS class
add unit test for L-BFGS used the same result produced by the Newton method
Revert "remove the useless code optimization for matrix mulitiplication"

This reverts commit 1c39d9b2ac6a467482b0cb514c766d3c6c885001.
Revert "chang the order of matrix multiplication to gain improvement"

This reverts commit 7b8cf6d68433710e7aa10139e04b79c2b70d2c9e.
Revert "enable unit test"

This reverts commit 9babe6542d10c65feb00bff820f00b6d14a40ab0.
add corresponding Matlab code for the LaplacianInferenceMethod_unittest
Revert "add unit test for L-BFGS used the same result produced by the Newton method"

This reverts commit fa83523ebbf59905efbe0bd3a8294776527ae6d9.
Revert "add corresponding Matlab code for the LaplacianInferenceMethod_unittest"

This reverts commit 10e7de7fea07b0ee8037eb2011fab2c8c92d9d2e.
add the corresponding Matlab code