new strings translated
Update strings.xml

some corrections
Code cleanup : replace "<expr> == false" with "!<expr>"
Code cleanup: remove space and tab at end of line
Code cleanup: remove unused imports
Code cleanup: remove duplicate color def, and move color def
Code cleanup: use 4 spaces, not tab for indentation
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