Merge pull request #1 from JyunjiKondo/develop

Change package name and class name
Merge pull request #2 from JyunjiKondo/develop

Remove unnecessary classes
rename class, meta-data and fix debug messages
Remove unnecessary methods
Fix comments
Remove unnecessary import declaration
Suppress lint warnings
Change eclipse project setting
Change ant build file
Merge pull request #3 from JyunjiKondo/cleanup

Clean up codes
Update gradle build setting
Make gradlew work
Remove unnecessary test cases
Change test cases' package
Rename test case
Make tests run correctly by reviving some methods
Make tests run correctly
Add Travis CI configuration