simplified date formatters
disabled home/up-button on first activity (fixes #32)
fixed compability bug on Android 2.3 for ArrayAdapter-methods
using gson with a stream to prevent OutOfMemoryException's
fixed bugs in gson's parser
serialize addresses and collections as list instead of each element separately
save user address in same cachelocation as in previous app versions
load and parse addresses in the preferences-screen instead of in the main screen
Merge pull request #35 from wpinnoo/cache-optimalizations

Cache optimalizations (closes #30)
added refresh button in AddressListActivity (closes #34)
Merge of master into widget branch