Add hostegl bld.inf info for building exporting and building the library. Note: uses tools/x86tool extension from /sftools/dev/hostenv/cpptoolsplat/symport/flm, which doesn't quite work right yet. SYS_INCLUDES needs adding to .xml, for example. Fixup warnings in hostegl when built using GCC.

holdingarea/build_vs200*
holdingarea/bin/
holdingarea/lib/
holdingarea/vg/bin/c_utils.pyc
holdingarea/build/
build/
hostsupport/hostopenvg/genheader/c_utils.pyc