[Android] Copy missing file for XWalk library project after rebasing to 31.

* Copy ImageFormat.java to XWalk library project as it's added in version 31 and
it's essential.
* Change the API level to 18 in project.properties for Eclipse.
* This will require Eclipse/ADT to update the SDK to version 18.

BUG=
[Android] Add custom version tag in build.xml for xwalk_core_library

The custom version tag is to prevent the build.xml being updated
by tools like 'android update project'.
It is needed by the cli for xwalk cordova container.
Merge pull request #846 from sqliu/rebase-for-library-project

[Android] Copy missing file for XWalk library project after rebasing to 31.
Finish migrating from googleurl/src/gurl.h to url/gurl.h.

Chromium M31 has wiped out the googleurl directory and merged the googleurl
repository into the Chromium one.

I guess the build bots (and the developers' checkouts) kept src/googleurl/
around for some reason and the build did not fail before, but the canaries,
which start from a fresh checkout every time, were failing:

../../xwalk/runtime/browser/android/net/android_protocol_handler.cc:14:32:fatal error: googleurl/src/gurl.h: No such file or directory
Merge pull request #852 from rakuco/gurl-includes

Finish migrating from googleurl/src/gurl.h to url/gurl.h.
[Tizen] Fix build break caused by new ffmpeg

Tizen 2.x platform have gcc version 4.5 which breaks compilation of new ffmpeg.
Break is caused by pragmas that are used inside functions. This patch modifies
configuration of ffmpeg (chromium/linux/ia32) and disables pragmas.
Merge pull request #854 from alexshalamov/fix_ffmpeg

[Tizen] Fix build break caused by new ffmpeg
[Tizen] packaging: Explicitly specify our Python version as 2.7.

Tizen 2.1 (and possible later versions as well) use Python 2.7 instead of
2.6, so pass that to Chromium's python_arch.sh.

We were supposed to pass that ever since we started packaging Tizen, but
there are two things to take into account:

- The CPU architecture in python_arch.sh is only used to special-case some
  stuff for MIPS, so this wasn't impacting us negatively before.

- Things were still supposed to work even if we didn't specify
  `python_ver', but my own commit 211783 upstream has shown a bug in the
  file(1) shipped by Tizen 2.1: `file --dereference /does/not/exist' returns
  0 instead of 1, which made python_arch.sh follow a pathological code path.
Merge pull request #858 from rakuco/tizen-python_ver

[Tizen] packaging: Explicitly specify our Python version as 2.7.
[Tizen] Fix for build break caused by new version of NSS

Chromium requires new version of NSS => 3.14.3, while Tizen
has NSS version 3.12.9.This patch switches xwalk to use
openssl, until Tizen gets upgraded version of nss package.
[BuildFix] Fix build for -Dcomponent=shared_library

After rebasing to Chromium M31, Crosswalk stopped building when
gyp_xwalk is invoked with '-D component=shared_library' [1], throwing
several linking errors. This patch fixes the build by adding missing
dependencies to xwalk.gyp.

BUG=https://github.com/crosswalk-project/crosswalk/issues/859

[1] https://code.google.com/p/chromium/wiki/LinuxFasterBuilds#Dynamically_link
[Android] Notify XWalkClient instance when the page has started to load

When starting to navigate a page, we should notify XWalkClient that the page
has started to load, and give it a chance to call its onPageStarted
callback function. This follows the way Chromium AwContentsClient does.

BUG=https://github.com/crosswalk-project/crosswalk/issues/851
Merge pull request #847 from wang16/cordova_container

[Android] Add custom version tag in build.xml for xwalk_core_library
Merge pull request #855 from hmin/onpagestarted

[Android] Post a message when the page is starting to load
Merge pull request #860 from hmin/shared-build

Make XWalk can be built with -Dcomponent=shared_library
Merge pull request #857 from alexshalamov/fix_nss_break_use_openssl

[Tizen] Fix for build break caused by new version of NSS
WIP: Lazy loader, runner on demand