protobuf: Clean up and update to version 2.6.1.

The upstream URL has changed as well as the download URL. I'm using the
archive from GitHub directly now, because version 2.6.1 hasn't been
uploaded to Google Code yet.

Changed the meta.license attribute to BSD3, because I haven't actually
found anything regarding "mBSD" on the web, so I'm guessing it should
mean "modified BSD". After digging up a bit more, there seems to be
overall consensus on BSD3/"new BSD" license, because it's BSD3 with
copyright of Google Inc. on the license.

Signed-off-by: aszlig <aszlig@redmoonstudios.org>
chromium: Update all channels to latest versions.

With this commit, the following new upstream versions are introduced:

stable: 38.0.2125.101 -> 39.0.2171.65
beta:   39.0.2171.19  -> 40.0.2214.10
dev:    40.0.2182.3   -> 41.0.2224.3

We can now remove missing_alg_import.patch, because version 39 is nom
stable and thus fixes the missing include directive upstream.

However, starting with version 40, we hit a few bugs with system
protobuf, so we're disabling it for every version >=40 to avoid
runtime/startup errors.

Here is the stable channel announcement for version 39 on the official
blog:

http://googlechromereleases.blogspot.de/2014/11/stable-channel-update_18.html

Signed-off-by: aszlig <aszlig@redmoonstudios.org>
chromium: Allow env vars for passing plugin paths.

Introduces environment variables to set plugin base paths. The schema
for these is like NIX_CHROMIUM_PLUGIN_PATH_<N>. Where <N> is the path
type we want to change, the supported (full) variable names are:

 * NIX_CHROMIUM_PLUGIN_PATH_ALL
 * NIX_CHROMIUM_PLUGIN_PATH_PEPPERFLASH
 * NIX_CHROMIUM_PLUGIN_PATH_FILEFLASH
 * NIX_CHROMIUM_PLUGIN_PATH_PDF
 * NIX_CHROMIUM_PLUGIN_PATH_FILE_EFFECTS
 * NIX_CHROMIUM_PLUGIN_PATH_NACL
 * NIX_CHROMIUM_PLUGIN_PATH_PNACL
 * NIX_CHROMIUM_PLUGIN_PATH_WIDEVINE

Whereas NIX_CHROMIUM_PLUGIN_PATH_ALL is the plugin base path for every
path which is not set explicitly, so by setting ..._ALL and not setting
..._WIDEVINE, the widevine plugin will be searched in the directory
specified using ..._ALL.

Right now, the only plugin where this is used is widevine, and it still
doesn't properly work yet.

Signed-off-by: aszlig <aszlig@redmoonstudios.org>
cups: bump 1.5.4 -> 1.7.5
chromium: Switch to use open-source PDF plugin.

The Chromium PDF plugin is now available as open source software and is
already included in the Chromium source tree in current stable, so there
is no need to extract it from the Chrome binary package anymore.

See release announcement at http://blog.foxitsoftware.com/?p=641

Signed-off-by: aszlig <aszlig@redmoonstudios.org>
Merge branch 'chromium'.

This introduces Chromium 39 as the new stable version along with a bunch
of fixes.

Fixes #2799, particularily the PDF plugin, which now is open source and
thus no longer an issue.

Also fixes #3219 and merges #2906, so we no longer get a crash while
trying to bring up the print preview dialog.

Thanks to @edwtjo for the CUPS version bump.

 * chromium: Switch to use open-source PDF plugin.
 * cups: bump 1.5.4 -> 1.7.5
 * chromium: Allow env vars for passing plugin paths.
 * chromium: Update all channels to latest versions.
 * protobuf: Clean up and update to version 2.6.1.