Mass updated... (It's not good.. but... sigh...)

* 'configure' hash new option '--with-debug' to test modules.
* 'Android.mk' now works well in Android NDK.
* Tool(wrlic) for adding license comments, is newly introduced.
  + license comment is updated
* 'yret' related files are removed (no more used.)
  (error number + integer return value are used instead of 'yret')
* 'ahash' is removed because 'hash' already has 'ahash' features.
* 'ydynb' is fixed and works.
* 'yset' - wrapper of 'yhash' - is newly introduced.