Research MXE compile warning about IPC

[shane-kerr]

We get the following warning from our MXE cross-compile in a couple of places during our Qt build:

src/qt/qtipcserver.cpp:22:2: warning: #warning Compiling without BOOST_INTERPROCESS_HAS_WINDOWS_KERNEL_BOOTTIME and BOOST_INTERPROCESS_HAS_KERNEL_BOOTTIME uncommented in boost/interprocess/detail/tmp_dir_helpers.hpp or using a boost version before 1.49 may have unintended results see svn.boost.org/trac/boost/ticket/5392 [-Wcpp]

We're using Boost 1.60, so that should not be a problem, but maybe we have to define one of the two defines there for our Qt build?

We need to figure out what these messages mean and deal with them in any case.