Merge pull request #37 from juzam/master

Updated strings reflecting new branding. mqttitude -> owntracks
Fixes #38, Fixes #36
Refactored preferences, Fixed publish ticker being shown after disabling and enabling preferences
Removed double notification action after disabling/enabling notification
Fixed some hint issues, improved notification handling
Android-v.0.4.18 APK
Fixed #4, Fixed #39
Fixed #40 (again)
Android-v.0.4.19 APK
Removed not needed publish button
Fixed #41, Fixed layout issues on API <= 16
Started working on #8
Moved database handling to App class to prevent possible crash when ServiceApplication was not yet initialized
Added additional saveguards to ensure that a service connection is established
fixed blurred actionbar background
Android-v.0.4.20 APK
Refreshing geocoder for tracked contact
Update README.md
Code cleanup
Added resources for other resolutions