Parse install_if from package metadata and include it in the
indexes. Also setup the reverse install_if dependencies when
loading a database. ref #443.

Actual install_if functionality is not yet implemented.

Just disable installation of packages using the new stuff. Also
flag lower case package info fields as non-critical and allow
installation even if that features is not supported.

otherwise we get reads from uninitialized/unallocated memory.

When package is installed from commandline, we should always
install that specific instance of package (never favor repository
version if it has difference identity). Otherwise we might not
always end-up installing the .apk given on command line. The
dependency is now against specific checksum identity (marked
with >< dependency comparison). Fixes #492.

.. instead of the longer flag combo.

Also re-exec's apk-tools to perform rest of the upgrade using
the new apk-tools. This allows handling of new apk-tools features
properly. Fixes #140.

It's no longer needed or used.

The version now needs to be initialized atom always, since it's
dereferenced in various places.

I think there used to be problems with using http_proxy on bb wget,
but those have been fixed for quite some time. This fixes #347.
We should probably use libcurl or similar library eventually, but
I'm not entirely sure if/when we want that.

The boundary callback should not happen until all the uncompressed
data has been consumed. This previously seems to have worked
because normally gzip library returns "no error" instead of the
"stream end" if we extract exactly the amount of bytes remaining
in the archive. (Perhaps this was changed in new zlib.) In any
case, verification was broken with some apks due to this callback
ordering issue.

 - implement a hash table for commonly shared fields such as
   license, version and architecture
 - use macroes to print blobs or pkgname-pkgver strings
 - fix some old cruft

Architecture is now:
 - parsed from .PKGINFO
 - written to index and installed db
 - appended to repository URL when fetching files

Unsigned indexes should not be needed anymore anyway.

should not be needed anymore.

.. instead of the pkgname-pkgver string.

 * prunes the child pid to avoid zombies
 * handles the errors so e.g. file-not-found is reported properly

blob.ptr might be non-null on empty field in /var/lib/apk/installed
so we compare with blob length.

This fixes a segfault on x86_64.

The hash is 'unsigned long' everywhere which is 64-bits (on 64-bit
boxes). Fix the one instance of it being 'unsigned int' since that
would be 32-bit and cause lookup failures on 64-bit boxes.

id cache needs to be initialized early. and group database filename
is surprisingly 'group'.

Otherwise we end up using wrong uid/gid mappings when doing install
to alternate system root. Fixes #434.

the uid and gid are used in other places than just changing file
ownership on extraction.

We want remove dirs when they are unreferenced so we remove all dirs on
apk del, but we don't want remove dirs when closing database. So we make
removing dir optional when unreferencing it.

This partially reverts commit c7ffc96a.

fixes #406

Seems like recent eglibc requires that you include sys/stat.h

We want minimal static build. And this now also breaks with our openssl
since it tries to automatically dlopen some of the engine modules.

That way we can set sh options case by case

We we can upgrade rest of system just fine then.

Installed package does not need to be checked for availability.
Account for packages missing if they get pruned out due to
installability check.

The trigger list can be reused after it's cleared, make sure
the list node is initialized all the time.

Make the libapk and lua module optional at buildtime and off by default.
This is because enabling libapk requires that mkinitfs also copies the
libapk.so or the initramfs will not work.

To build libapk:

 make LIBAPK=yes

To build lua module (will enable LIBAPK=yes):

 make LUAAPK

To link apk to libapk (will enable LIBAPK=yes):

 make SHARED_LIBAPK=yes

All the above applies to make install target as well.

So open the db in read-only mode instead. This allows --simulate to
be run as non-root user.

Take the uid/gid from passwd and group.