Revert the url distinguistion from "Implement Android Beam (NFC Sharing) for cgeo", as it seems the // urls don't work anymore.

This partly reverts commit a0825983139c99a9799503cafdf0dd0e3ce54a2f.
Implement a small internal browser (using webview) and allow the user to pick the user to select an internal/external browser if c:geo is the default of the geocaching url
Merge pull request #3901 from schwabe/internal_webview

Internal webview