Remove compiler warnings in CC7

[tswilliams]

Jeroen noticed in the CC7 alpha RPMs that uhal/Utilities.hpp produces the following compiler warning:

 In file included from
 /opt/cactus/include/uhal/ProtocolControlHub.hpp:46:0,
                  from
 /afs/cern.ch/work/j/jhegeman/cms_tcds/sw_devel/cmsos/trunk/daq/tcds/hwlayertca/src/common/HwDeviceTCA.cc:14:
 /opt/cactus/include/uhal/Utilities.hpp: In function ‘bool
 uhal::utilities::HttpGet(const string&, uhal::HttpResponseType&)’:
 /opt/cactus/include/uhal/Utilities.hpp:259:36: warning: typedef
 ‘BufferTypeIterator’ locally defined but not used [-Wunused-local-
 typedefs]
        typedef BufferType::iterator BufferTypeIterator;
                                     ^

Full details: https://svnweb.cern.ch/trac/cactus/ticket/2144

We should fix the source of compiler warnings where possible