Move master change log to res/xml/changelog_master.xml

Benefits of this location over res/raw/:

The file will be compiled and stored in a binary format by aapt
which should speed up processing the file when reading.

The XML syntax will be validated by aapt when building.
If the syntax is invalid, the build will fail.
Fix sample app to use the new changelog_master.xml file
Merge pull request #3 from zjw/validate_changelog

Move master change log to res/xml/changelog_master.xml
Add German translation of sample app
Change line endings from CRLF to LF
Update list of contributors
Update changelog in README
Change links to screenshots
Cosmetic changes to README
v1.0.0