Add plugin for screen orientation

[psvensson]

This one, for example;

https://github.com/gbenvenuti/cordova-plugin-screen-orientation

Requested by community

[gokr]

Moving to Fredrika which needs a new viewer most probably.

Added in this commit: a6d8702

TODO:

• DONE Make tests to verify that the plugin works. See test results below.
• Update documentation page with plugin listing (API page)

Status update:

Test results for iOS:

• Report of screen orientation works (screen.orientation, and orientation changed event).
• Set screen orientation does not work.

Test results for Android:

• Report of screen orientation does not work.
• Set screen orientation works.

Conclusion: the plugin is half working on both Android and iOS, with different functionality working/failing on respective platform.

Should we include the plugin given these conditions? The result could be confusion/frustration among users.