[PATCH v2 00/13]: Add asdf-build-system.

[Andy Patterson]

Here's the next round of the series. In addition to the changes proposed by
宋文武, I homogenized the phases of the compiled packages, in order to
simplify transformations. I also added a package transformer system similar to
package-with-python2. Finally, I decided to have all packages bundle a copy of
their source, and use it while building, rather than using the source packages
as a build input, which had some complications.

Further comments are appreciated.

Thanks,

--
Andy