Support local agents

[Bruno Rosa]

According to the following comments made by Adrian Deccico, the HungBuildKiller add-on does not support local agents, only remote agents:

• https://jira.atlassian.com/browse/BAM-931?focusedCommentId=540111&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-540111
• https://jira.atlassian.com/browse/BAM-931?focusedCommentId=540115&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-540115

It would be nice if the HungBuildKiller add-on could kill hung builds run on local agents as well.