create Makefile to build from source

[tiendung]

Mình muốn build từ source mà ko có Makefile nên mày mò chưa ra.

[iamloivx]

@ledongthuc updated the liblinear and write two scripts to build DongDu.
https://github.com/ledongthuc/DongDu

Via them, I write a simple Makefile at https://github.com/iamloivx/DongDu/blob/master/Makefile and create a new pull request to @ledongthuc project.

Note: The Makefile only works for @ledongthuc forked project. Seem that @rockkhuya has not maintained the DongDu for two years, @ledongthuc project should be our selection.