Intellij config: JDK setup: switch interpolation markers in dev-tools/idea/.idea/misc.xml to be well-formed (unlikely-to-be-used XML attribute 'subst.="idea.jdk"'), so that in-place users won't be yelled at by Intellij.  When IntelliJ starts up without this 'attribute' having been interpolated, it ignores and then removes the unknown XML attribute.

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1524916 13f79535-47bb-0310-9956-ffa450edef68