CB-6218 Update docs for BB10
Add necessary capability so the plugin works on its own
CB-6389 CB-3617: Add clearcache and clearsessioncache options to iOS (like Android)
CB-3617: Document clearcache and clearsessioncache for ios
CB-6422 [windows8] use cordova/exec/proxy
CB-6402 [WP8] pass empty string instead of null for [optional] windowFeatures string
Make InAppBrowser work with embedded files, using system behavior

The plugin is changed to work with embedded files, using the system behavior. If one needs the system behavior, they need to pass "_system" as target when using the plugin. As the InAppBrowser for WP8 does not handle by itself the embedded pdf files, system behavior is called.

The plugin also is tested and working for wp7
Merge branch 'wp8-work-with-embedded-files' of https://github.com/Icenium/cordova-plugin-inappbrowser into dev
await async calls, resolve warnings
CB-3324 Add support for back-button inappbrowser [WP8] if there is no history -> InAppBrowser is closed
CB-6360: Fix for crash on iOS < 6.0 (closes #37)
CB-6460: Update license headers
CB-6452 Updated version and RELEASENOTES.md for release 0.4.0
CB-6452 Incremented plugin version on dev branch.
CB-5649 - InAppBrowser overrides App's orientation
CB-6360 - improvement: feature detection instead of iOS version detection
Fixed use of iOS 6 deprecated methods
CB-6474 InAppBrowser. Add data urls support to WP8
CB-6482 InAppBrowser calls incorrect callback on WP8
Merge branch 'CB-6482' of https://github.com/sgrebnov/cordova-plugin-inappbrowser into dev