Replace some boost_foreach with range-for

indra/llcommon/llleaplistener.cpp

indra/llcommon/llprocess.cpp

indra/llcommon/llsingleton.cpp

indra/llcommon/llsys.cpp

indra/llcommon/tests/lleventdispatcher_test.cpp

indra/llcommon/tests/llleap_test.cpp

indra/llcommon/tests/llprocess_test.cpp

indra/llcommon/tests/llsdserialize_test.cpp

indra/llcommon/tests/llstreamqueue_test.cpp

indra/llcommon/tests/lltreeiterators_test.cpp

indra/test/test.cpp