New version of Activiti Modeler (Angular JS) and upgraded to 5.17.0
Adding tests for AsyncExecutor + support for executors nodes going down and jobs being picked up by others
Merge branch 'master' of https://github.com/Activiti/Activiti

# By Tijs Rademakers (2) and nosovp (1)
# Via Tijs Rademakers
* 'master' of https://github.com/Activiti/Activiti:
  New version of Activiti Modeler (Angular JS) and upgraded to 5.17.0
  Manual fix for pull request 476
  Update of joda-time library (from 2.1 to 2.6) to support timezone changes in some countries, e.g. in Russia.
Fix for failing AsyncExecutorTest
Fix for failing AsyncExecutorTest (part2 - always cleaning up)
Fix for mssql upgrade (typo in table name)
Fix for failing AsyncExecutorTest (part3 - tough one)
Fix history index upgrade script
Merge branch 'master' of https://github.com/Activiti/Activiti
Fix for failing AsyncExecutorTest (part4: adding logging + changing the way was waited for jobs to be finished, not shutting down the executor)
Add support to get variables when starting a process instance
Merge branch 'master' of https://github.com/Activiti/Activiti