Use of boost::make_shared in qana and qdisp

For classes:
* lsst::qserv::qana::ScanTablePlugin
* lsst::qserv::qana::TableInfoPool
* lsst::qserv::qana::TablePlugin
* lsst::qserv::qana::WherePlugin
* lsst::qserv::qdisp::Executive
Use of boost::make_shared in qproc

Second pass