Clean up a ton of double and float conversion warnings

indra/llappearance/llpolymorph.cpp

indra/llaudio/llaudioengine.cpp

indra/llaudio/llwindgen.h

indra/llcharacter/llbvhloader.cpp

indra/llcharacter/lljointsolverrp3.cpp

indra/llcommon/llfasttimer.cpp

indra/llcommon/llframetimer.cpp

indra/llcommon/llframetimer.h

indra/llcommon/llmetrics.cpp

indra/llcommon/llstatsaccumulator.h

indra/llcommon/llsys.cpp

indra/llcommon/lltimer.cpp

indra/llcommon/lltraceaccumulators.cpp

indra/llcommon/lltraceaccumulators.h

indra/llcommon/lltracerecording.cpp

indra/llcorehttp/httpstats.cpp

indra/llimage/llimagefilter.cpp

indra/llimage/llpngwrapper.cpp

indra/llinventory/lllandmark.cpp

indra/llmath/llmath.h