extras: halide: support generation of arbitrary outputs
Issue 1487 - there can be race conditions or other kinds of errors to ignore
intltool: add style option to intltool_in

This allow to user to get abstracted about the passed intltool-merge
flags, so this code:

    bld(
        features = 'intltool_in',
        flags    = ['-d', '-q', '-u'],
        source   = 'myapp.desktop.in',
    )

Now is equivalent to:

    bld(
        features = 'intltool_in',
        style    = 'desktop',
        source   = 'myapp.desktop.in',
    )