[Android] Implement the feature about visited link.

This patch is to implement the feature about visited link.
"a:visited" does not work when the url was clicked, so this feature
should be implemented.
Most of the code was ported from android webview.

BUG=https://crosswalk-project.org/jira/browse/XWALK-986
[Android] Remove unnecessary pak file loading for sandboxed process.

Since XWalk is ALWAYS running in single process mode, the pak file loading
for sandboxed process is never be used.

BUG=
[Tizen] [Runtime] Fix the issue that widget apps fails to install without version attribute.

It reports installation crash if a widget app doesn't contains
widget 'version' attribute in the config.xml file. The root cause is
Version::GetString() always assumes a Version instance is valid, in
other words, not an empty string.

Due to the 'version' attribute could be optional for widget app, a
solution to fix this issue is we add check in
ApplicationData::VersionString().

BUG=XWALK-1226
[Android] Add the test cases related to wrong permissions in packaging tool.

Since there is no negative permission test case in packaging tool for
command-line mode, this pull request adds the test cases of setting
wrong permissions in packaging tool.

BUG=XWALK-1249
[Tizen][Runtime] Implement widget preference attribute.

The 'preferences' attribute allows authors to manipulate a widget
storage area that is unique for the instance of a widget. It does this
by implementing the Storage interface specified in
http://www.w3.org/TR/webstorage/

Spec:
http://www.w3.org/TR/widgets-apis/#the-preferences-attribute

This CL implements the below features,
1. Web Storage functions and attributes, includes,
   length, getItem(), setItem(), removeItem(), clear().
2. 'readonly' field support for the key/value pairs.
3. Remove the widget database file when uninstallation app.
4. Load Manifest configuration when creating widget DB.
Merge pull request #1713 from shaochangbin/widget_handler_preference

[Tizen][Runtime] Implement widget preference attribute.
Merge pull request #1724 from shaochangbin/fix-bugs

[Tizen] [Runtime] Fix the issue that widget apps fails to install without version attribute.
Bump canary to version 6.
Merge pull request #1733 from darktears/bump-6

Bump canary to version 6.
Merge pull request #1722 from sqliu/pak

[Android] Remove unnecessary pak file loading for sandboxed process.
Merge pull request #1682 from wuhengzhi/visited_link_color

[Android] Implement the feature about visited link.
[Android] Fix white screen issue when load http.html with manifest.

Correct the judgment of url schemes in xwalk_content.cc.

BUG=https://crosswalk-project.org/jira/browse/XWALK-985
[Tizen][Runtime] Add "allow-navigation" handler for Tizen legacy WGT
package.

This element defines a list of URL domains that are allowed to be navigated in the Web
Application window for Tizen legacy WGT.

Please refer to
https://source.tizen.org/sites/default/files/page/tizen-2.2-wrt-core-spec.pdf
for more details.
Merge pull request #1726 from ShDavidliu/PermissionCase

[Android] Add the test cases related to wrong permissions in packaging t...
Merge pull request #1729 from takethathe/allow_navigation

[Tizen][Runtime] Add "allow-navigation" handler for Tizen legacy WGT package.
Bump version to 6.34.107.0
Merge pull request #1735 from gaochun/bug985

[Android] Fix white screen issue when load http.html with manifest.
[Android] Enable ssl connection with untrusted certificate.

If the server has an untrusted certificate, nothing will be displayed in
current implementation. Enable to allow certification error by showing a
dialog to users to decide whether to accept it.
Need a test case from QA to verify it.

BUG=https://crosswalk-project.org/jira/browse/XWALK-1246
[Runtime] Enable WARP for WGT package

The Widget Access Request Policy (WARP) specification is a security
mechanism to control network access from within a widget application, as
well as a method for authors to request that the user agent grant access
to certain network resources or sets thereof by setting access tag in
widget config.xml file. e.g.
<access origin="http://www.sample.com" subdomains=true />

This will grant to access permission for all resources under
"http://www.sample.com" such as "http://www.sample.com/icon.png".

Using <access origin="*" /> will enable all network access. By default,
if no access tag is given in config.xml, only local widget resources can
be accessed.

The reference link is http://www.w3.org/TR/widgets-access/.
[Runtime] Fix onLaunch event is not fired under service mode.

Bug reports 'webapi-runtime-xwalk-tests' cases are failed to launch.
Root cause is onLaunched event is not sent under run-as-service mode.
The patch fixed above issue.

BUG=XWALK-1228