Modernizing dSploit

_This pull-request aims at modernizing dSploit in terms of design, tooling and UX._

The following changes were made, in a separate "gradle" branch:

- Integration with the new Gradle-based android build system as well as the Android Studio IDE
- Full refactoring of the user interface, for a more modern, Holo-compliant design (see screenshots below)
- dSploit is now almost fully translatable (the plugins will need their constructors to be refactored to make the plugin selection screens translatable)
- Added partial French translation
- A lot of refactoring and use of syntactic sugar for a cleaner code which is more compliant with the Java conventions, as well as some performance tuning and extra error-checking


A signed apk of dSploit including those changes can be found at the following link: https://github.com/Androguide/dsploit/raw/gradle/dSploit.apk



__Screenshots__:

![screenshot 06-30pm sep 25 2013](https://f.cloud.github.com/assets/2505731/1210894/eaea7536-2600-11e3-8f4f-52f79a2453e1.png)
![screenshot_2013-09-25-18-27-53](https://f.cloud.github.com/assets/2505731/1210890/eadf4da0-2600-11e3-87e6-1fb6025c6cdc.png)
![screenshot_2013-09-25-18-28-16](https://f.cloud.github.com/assets/2505731/1210891/eae0be4c-2600-11e3-89f4-3656bc21be0b.png)
![screenshot_2013-09-25-18-28-05](https://f.cloud.github.com/assets/2505731/1210892/eae49558-2600-11e3-8820-018f0c975276.png)
![screenshot_2013-09-25-18-26-50](https://f.cloud.github.com/assets/2505731/1210893/eae92398-2600-11e3-8bef-f902f256569d.png)