Update Spanish translation #527
Improve the source viewer in newer Android versions
Merge pull request #529 from AmauryEsparza/master

Update Spanish translation #527
Upgrade the targetSdkVersion to 21

JavascriptInterface annotations must be added to the SourceEditor for
JavaScript calls to continue working.
Merge pull request #621 from jonanp/new-sdk

Update SDK to v21
Merge pull request #622 from jonanp/improve-sourve-editor

Improve the source viewer in newer Android versions