Merge pull request #20 from pdpiech/development

Add ProGuard optimization and Google Play Services check
Merge pull request #22 from pdpiech/development

Fix laundry list duplication bug
Merge pull request #24 from pdpiech/development

Add weather background, fix bugs, secure code
Merge pull request #26 from pdpiech/development

Delete files, update twitter4j to v4, tweak code
Increment versioning for release

- Increment version number for release on Google Play Store
- Add link in README.txt to Google Play Store application
- Add Google Play Store promo image
- Move around some image files
Merge branch 'development' into release