builddep: Support the --with/--without options to toggle bconds

[dm0-]

This adds the same options used by rpmbuild, mock, etc. for setting macros to flip build-time conditional switches when parsing spec files. It provides a consistent interface across related tools.

They are aliases in rpmbuild, I'm not sure if there is a better way to accomplish something like that here:

rpmbuild alias --with           --define "_with_!#:+     --with-!#:+" \
        --POPTdesc=$"enable configure <option> for build" \
        --POPTargs=$"<option>"
rpmbuild alias --without        --define "_without_!#:+  --without-!#:+" \
        --POPTdesc=$"disable configure <option> for build" \
        --POPTargs=$"<option>"