new strings translated
Update strings.xml

some corrections
updating the term "update" to "upload"
DataManager: check dir existence before creation
use transifex for translation
added travis ci
enabeld travis ci email notifications
Merge pull request #68 from alfh/fix_code_cleanup

Code cleanup to make code more consistent
Merge pull request #66 from Logan676/master

updating the term "update" to "upload"
Merge pull request #69 from alfh/fix_check_dir_before_mkdir

DataManager: check dir existence before creation
Merge pull request #53 from rcoss/master

new strings translated
Merge pull request #61 from to-ba/patch-1

Update strings.xml
removed duplicated strings in es_AR lang
DbHelper: Make method to get instance synchronized
The DbHelper classes should be a singleton, but then the
method to get the singleton instance should be synchronized, in
case several threads are trying to get hold of an instance.
DatabaseHelper: fix repoDirExist check againt db
DataManager: Only calc thumbnail size if file exists
Code cleanup: remove public, abstract qualifier from public interfaces
Code cleanup: remove unused imports
Update dependencies to newest version
Also make the README.md versions in sync with the actual versions
being used in the pom.xml file.

This change has not been much tested, have just compiled and
done some initial tests.
DataManager: Refactor by making a new private method
Make new private method, and use it from three places, to avoid code
duplication.
Make some public static methods private static, since they
are only used internally in the class.