XD-1819 Runtime executables share jars in xd\lib

This reduces the size of XD dist zip from 390.4MB (M7)  to 252.3MB -- about 25MB due to discontinuing support for older Hadoop distros (XD-1854 applied after rebase).  This is accomplished by configuring xd-shell, hsqldb-server, and gemfire-server, to share jars already in xd/lib.  The build is modified to exclude such jars from the distribution and the runtime scripts are modified to add xd/lib  to the classpath.  I have started up and smoke tested these runtimes on Mac and Windows XD.   

Further space savings can be achieved by normalizing duplicate jars in the module lib directories. However there is some major work on the Module Registry proposed for 1.x, so this should be addressed then.  
I also noticed $APP_HOME/lib is empty in case spring-xd-batch project as all the dependencies exist in spring-xd-dirt. It is nice that we have this path included for any future additions.