Added XML serializer from andorid sources
Moved class to avoid ambiguity, compilable under api 4+
Failing test for #2635
Fixes #2635, crash during gpx export

Added utf-16 codepoint surrogate handling to xml serializer
Merge branch 'release' into upstream

Conflicts:
	main/src/cgeo/geocaching/export/GpxExport.java
Prevent StaticMapsproviderTest.java from getting run

StaticMapsProviderTest.java fails more often than not because the image
quota on the test server has been reached. Until we find a way to test
static maps download more reliably, for example through a mock download,
the test is disabled.
Remove progress bar on image loading
Remove unused strings
Add indefinite progress bars when loading images