*****************************************************basics package******************************************************************************

Supported utilities:
ec_log.h: simple logger
ec_config.h: simple configuration, supports cache
ec_regex.h: simple regex
ec_utils.h: supports string, URL, fileIO utils

ec_linear_classifier.h: simple linear classifier
ec_boolean_classifier.h: boolean classifier, supports A >= 1 && B < 2 || C == 1 && !D==2
ec_svm_classifier.h: wrappers libsvm

Notes: src codes just depend on STL except ec_Linux dependent regex.h/.cpp
0. almost all the source code are written by myself, except some minor updates;
1. ec_log.cpp has ANDRIOD specific code, it's not thread safe;
2. ec_svm.h/.cpp is copied from third party libsvm, extended by switch  __SVM_EXTENSION_ENABLED__, which ec_svm_classifier.cpp depends on;
3. json/ is copied from third party, I never used yet, while used by others, their header files are not in inc/ folders;
4. ec_regex.h/.cpp just support Linux platform;
5. unit test depends on gtest-1.6.0+;
6. ec_log.h, ec_iconfig.h, ec_iregex.h are pure interfaces, can be implemented for different platforms;