Add ctags command check in Makefile.
Read KALDI archive using popen().
Some refactoring and remove compilation warnings.
Make DataStream an abstract class. Unit tested.
[Bug Fixed] Missing return in some functions.
Merge branch 'feature/embed-kaldi-io' into develop
Change FILE* to C++ iostream style.
Use XML to store model file.
Add back dnn.init(). cnn runnable.
Use wget rapidxml-1.13.zip & save it to tools/.
Use enum rather string for convolution type.
Batch convn in feedBackward. Not tested thoroughly.
[Bug Fixed] accidentally use - in operator +.
[Refactoring] Move implementation to cnn.cpp
Add XML read/write functions for CNN.
Prettify dnn.status() and other tables.
Speed up CNN::backPropagate by 4.7 times.
Speed up CNN::backPropagate again by 2.87 times.
Add randn as an option in dnn-init. Some refactor.
[Bug Fixed] set this->_remained to 0 after rewind.