* Switch HOMEPAGE & SOURCE_URI to https.
* Do not pass --disable-rpath to configure, otherwise the build
fails if cmd:help2man is not in BUILD_PREREQUIRES.
* Define TEST_REQUIRES with cmd:{cmp,diff,help2man}. It might be
used by HaikuPorter in the future.
* Remove duplicate cmd:awk in BUILD_PREREQUIRES (and sort it).