Pull out common parts of method Makefiles into method_common.mk

src/methods/adaboost/Makefile

src/methods/approx_kfn/Makefile

src/methods/bayesian_linear_regression/Makefile

src/methods/dbscan/Makefile

src/methods/decision_tree/Makefile

src/methods/emst/Makefile

src/methods/fastmks/Makefile

src/methods/hoeffding_tree/Makefile

src/methods/kde/Makefile

src/methods/kernel_pca/Makefile

src/methods/kfn/Makefile

src/methods/kmeans/Makefile

src/methods/knn/Makefile

src/methods/lars/Makefile

src/methods/linear_SVM/Makefile

src/methods/linear_regression/Makefile

src/methods/lmnn/Makefile

src/methods/local_coordinate_coding/Makefile

src/methods/logistic_regression/Makefile

src/methods/lsh/Makefile