Revert "Remove log_cb, add ALPM_EVENT_LOG instead"

Moving logging to the event callback caused warnings
under clang due to non-literal format strings and
silenced all log messages when --print was used.

This reverts commit cd793c5ab7689cc8cbc18277375b368060e5acfe.

Signed-off-by: Andrew Gregory <andrew.gregory.8@gmail.com>

Conflicts:
	lib/libalpm/alpm.h
	src/pacman/callback.c
Signed-off-by: Allan McRae <allan@archlinux.org>
makepkg: break out check_checksums to reasonably sized functions
makepkg: break out checksum generation to its own function

This also fixes a "bug" in which a PKGBUILD without any source array
would generate "md5sums=()". While not technically wrong, we can easily
do better and emit nothing at all.
PKGBUILD: add support for arch-specific sources

This implements support for declarations such as:

  arch=('i686' 'x86_64')
  ...

  source=("somescript.sh")
  source_i686=("http://evilmonster.com/i686/ponies-9001-1.i686.bin")
  source_x86_64=("http://evilmonster.com/i686/ponies-9001-1.x86_64.bin")

  md5sums=('d41d8cd98f00b204e9800998ecf8427e')
  md5sums_i686=('e4ca381035a34b7a852184cc0dd89baa')
  md5sums_x86_64=('4019740e6998f30a3c534bac6a83f582')

Just the same as the "untagged" sources, multiple integrity algorithms
are supported. The manpage is updated to reflect support for these
suffices.

This commit also refactors download_sources slightly:

1) to use the otherwise preferred convention of lowercase local variable
names, and to make the handling of $1 more clear.
2) rename the "fast" parameter to "novcs", to make it more clear what
this token does.
3) add a new possible token "allarch" to ensure that download_sources
will fetch all sources, for all architectures.
updpkgsums: update to recognize arch-specific sources

This change reveals a bootstrapping bug -- since we call the bare
"makepkg" and rely on PATH lookup, we might not have a makepkg which
can generate architecture-specific checksums.
makepkg: abort if we can't add install/changelog to package
paccache: parse_filename bug fix

Filenames got parsed wrongly, causing whitelist- and blacklist-checks to
always return false. Caused by 8122fae51a when full path names to pkgs
were introduced.

Signed-off-by: Maxim Andersson <thesilentboatman@gmail.com>
makepkg: move negation in inequality comparisons

This commit changes the few remaining instances of:

  [[ ! $foo = "$bar" ]]

to the more common:

  [[ $foo != "$bar" ]]

Signed-off-by: Allan McRae <allan@archlinux.org>