Normalize line endings

Normalizes line endings by following steps at https://help.github.com/articles/dealing-with-line-endings
Adds .gitattributes so committed text files will have normalized line endings in the repository (LF rather than CRLF)
Updates current instances (9 files) to have LF rather than CRLF line endings
git diff --ignore-space-at-eol can be used to show that no other changes were made

Ran xmllint --format to correct formatting issues with Android schemas

Included Android schema documentation corrections provided by Tim Harrison of Booz Allen Hamilton