delete useless code

Change-Id: I40d32a70809feeaea77a0e23b9cd5a381b1265ff
separated lib and sample,
also rename some file to start with 'DL'
plugin in main sample do not depend on host any more
Added a sample to show how to make plugin-project depend on host-porject.
By this, plugin-project is able to use the whole host-project include res
remove unused file
remove unused file
Added a sample in which host-project implement a interface, and public the interface to plugin-project.
Merge pull request #7 from slovx2/interface

Separated lib and sample, and add two more sample
host and plugin refer to dl-lib as jar

Change-Id: Iecfd282b8dc3bd951295b741392daadbd5ff1cbd