Mopub mediated SDK and location may not be present

• Fixed an issue in location retrieval to get the latest available location not just rely on the most accurate
• Removed the automatic retries on Banner Ads.
• Corrected issues in MoPub adaptor , where it would silently fail and not load if the view was not visible.
• Improved public documentation.
• Refactored out of public classes internal interfaces.
• Additional unit tests