* Add configure option --bootstrap which allows specifying the
haikuporter and HaikuPorts repository paths.
* Add rules for supporting a second repository type. The
PackageRepository rule is now private and RemotePackageRepository is
used for remote repositories. The new BootstrapPackageRepository rule
is for defining a bootstrap repository (there will probably be only
the HaikuPorts cross repository) whose packages can be built as needed
via haikuporter.
* Rename DownloadPackage to FetchPackage.
* Define repository HaikuPortsCross.
* HaikuCrossDevel package(s): There are now two sets of packages: A
"stage1" set with the same content as before and a final set
additionally containing the libraries libbe, libnetwork, libpackage.
Those are needed for building the libsolv bootstrap package while for
building them we need other bootstrap packages (ICU, libz).
This is basically all that's required to build a bootstrap Haiku
completely from sources, with a few caveats:
* There's no ICU bootstrap recipe yet (so one has to cheat and use the
prebuilt package ATM).
* Probably doesn't work on Haiku yet (tested on Linux only).
* A 32 bit environment must be used (otherwise building the gcc 2
bootstrap package fails).
* Building with multiple jobs doesn't work yet, since haikuporter uses
common directories for building different packages and there's no
explicit serialization yet.
* Haven't tested the resulting image save for booting it. So it probably
needs a bit more work before it can actually build the final
HaikuPorts packages.
