Avoid need to modify qnx.pro in src/plugins/platforms/qnx to
build with imf support. By default detects if necessary headers
and libraries are available. Can also be explicitly requested or
disabled with -imf and -no-imf options.
Change-Id: I3f9780fc189a33e4c93fb4f950111121f8e947c3
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@digia.com>
