Updated viewport
Updated targetSdkVersion to leatest (19).

Fixes #198
Updated engine-android to use latest targetSdkVersion.
Rebased and fixed editor-android sdk version.
Updated android-maven-plugin to latest: 3.9.0 release candidate 1
Changelog: https://code.google.com/p/maven-android-plugin/wiki/Changelog
Merge pull request #274 from RotaruDan/targetSdkVersion

Updated targetSdkVersion to latest (19).
Merge pull request #266 from imartinezortiz/release-engineering

Release engineering (cleanup, lightened mvn clean install)
Improved filter-by-tag gallery functionality.
Added TagPanel and I18N tag related strings.
Fixed some bugs with several widgets.
Added final modifier to missing fields.
Added "final" modifier to some fields in editor-android project.
Merge pull request #273 from anserran/fit

Updated viewport in engine
Removed final modifier in catch sentence.
Merge pull request #284 from RotaruDan/tagsPanel

Improved filter by tag gallery functionality.
Now the PaintButton and EraserButton of ElementEdition are in other toolbar.
This toolbar appears when pressed add/paint new item.
Fixed visibility tool bar bug.
Removed some unnecessary classes
Added file chooser dialog and widgets related
Substituted old file chooser with new file chooser
Fixed minor bugs and added some comments