[Android] Add the application version in the package file name.

It is useful for the application developer to know which version of the
web application was packaged. This patch allows the published to add that
information while packaging the application by adding the handling process
of the application version in the packaging tool for shared mode and embedded
mode.

BUG=https://crosswalk-project.org/jira/browse/XWALK-908
Merge pull request #1538 from ShDavidliu/PackageNameAppVersion

[Android] Add the application version in the package file name.
[Android] Add execution permission for python scripts.

All these scripts should have execution permission so that they
can be ran like below:
./make_apk.py ...

BUG=https://crosswalk-project.org/jira/browse/XWALK-935