Set M2_Home for maven builds and add maven to the path so if the build
needs to run maven from maven (or maven from ant from maven) it can.

Otherwise plugin classes won't resolve.

Ant build step had quite a mix: buildFile and antOpts expanded against
env, properties against buildVariables, and targets against both.
Now merging buildVariables into env and applying to all.

 I added a mode where one can launch a child process without the built-in pumping support, making it trivial to read until EOF in the distributed environments.

 This concludes the fix.

as this content later gets eval'ed.  Javascript errors could occur when view names
or user names contained '

[FIXED JENKINS-7809] fixed a race condition in obtaining the tail of the output from remote process.

[FIXED JENKINS-7649] Only including one SCMTrigger.BuildAction per build, since there's only one possible polling log to link to.

While editing description, inline help should show the syntax guide based on the current markup formatter.

Note that the above description is incorrect as to what the merge was about.
It is the message that I intended to make. It appears that I accidentaly merged multiple fixes waiting to be reviewed on my private fork.

This reverts commit dce0d2af, reversing
changes made to 63f67f30.