fix act-1839
Fix double sequence flows
Added documentation on setting process variables.

* Moved main documentation to VariableScope#setVariable() and
VariableScope#setVariables();
* Updated descriptions for RuntimeService#messageEventReceived(),
RuntimeService#setVariables() and RuntimeService#setVariable to point to
main documentation;
Merge pull request #190 from tiesebarrell/master

Added documentation on setting process variables.
Removing distinct from task query to see impact on Jenkins (initiated by http://forums.activiti.org/content/activiti-sql-query-performance)
Merge branch 'master' of https://github.com/Activiti/Activiti
Fixing issue with export of event-listener
MNT-9765: Removing duplicate index on the same column
Removed vscrollarea.js due to conflicts in login-screen
Altered task-candidate test to include process/task variable count
Merge pull request #174 from smirzai/act-1082

fix act-1839