add checkstyle plugin and config file
add new blank line rules to checkstyle settings
Merge branch 'develop' into issue/670-refresh-code-style
new script to check introduced style errors
Merge branch 'develop' into issue/670-refresh-code-style

Conflicts:
	build.gradle
	src/org/wordpress/android/util/StatsRestHelper.java
Merge branch 'develop' into issue/670-refresh-code-style

Conflicts:
	build.gradle
test validation of WelcomeFragmentSignIn.java
dummy
checkstyle scripts
fix compare-with-develop-style script
enhanced compare-with-develop-style.sh script
import order
Merge pull request #1245 from wordpress-mobile/issue/670-refresh-code-style

fix #670 refresh code style