Normally we run ./configure from within the build tree, but autotools
now allows doing out-of-tree builds by running configure while cd'ed
to a different directory. Add a config variable `AUTOTOOLS_BUILD_PATH`
to allow this on a per-package basis, and set this for the SDL2
package; SDL2 hg complains when doing in-tree builds because certain
files get clobbered.
Since we're downloading arbitrary executable code from websites and
running it, we should at least have some confidence it's the right
thing we're running.
It's nice to be able to build from source control HEAD, and
especially for packages under than Chocolate Doom itself. As a start,
define "latest" variants for all the SDL2 packages.
The only place this is needed is when determining the directory name
that the tar file will be extracted to. This can be done by examining
the .tar file name without needing to know the version itself.
These modules encapsulate individual pieces of functionality and make
the code far more maintainable. This is a pretty big refactoring but
overall a big win.
Not sure what the practical upshot of this is yet, but it at least
allows it to build successfully. I've been unable to get it to build
with DirectX support enabled yet because the compiler complains about
missing header definitions for LPDIRECTINPUTDEVICE8 and related
functions.
This is a tricky package to support, since the tar file is improperly
structured and it is not an autotools package. Refactor slightly and
add IS_TAR_BOMB option for this kind of use case.
