This is a bug fix release for version 5.15 with an important MySQL upgrade fix.
In addition we refactored the version upgrade logic so you can install 5.15.1 on a 5.15 database without issues.
- Bug fix release for a MySQL upgrade issue (more details can be found here http://forums.activiti.org/content/important-activiti-515-and-mysql-56-users)
- Some small improvements from pull requests