Revised Gradle Plugin documents (#301).
Fixed Gradle Plugin bugs in eclipse plugin enhancement (#301).
Merge remote-tracking branch 'private/issue/301-M2' into 0.5-develop
Add application/migration-guide for version 0.5.2 (#301).
Modified target platform version (#310).
Fixed bugs generating apt pref on Windows (#301).
Fixed bugs evaluating extension path on Gradle Plugin (#301).
Add document for migrating gradle plugin (#301).
Release notes and changelogs for version 0.5.2 (#310).
Merge remote-tracking branch 'private/issue/301-M3' into 0.5-develop
Merge remote-tracking branch 'private/issue/310-M3' into 0.5-develop
Merge remote-tracking branch 'central/0.5-develop' into 0.5-release
Bumped version number to 0.5.2