Added gradle support to build the project
Added support for gradle & maven builds.

The organization of the repository is taken from https://github.com/JakeWharton/ActionBarSherlock
Added the sample project into the main repository
Include the sample app in the Gradle build process.
Ensure to use the latest SDK for all components.
Corrected README.md
Finally moved the demo application into its own directory swipelistview-samples/demo

Ensured the package name will be the same like the version released in the market.
Switched the central package

from:
com.fortysevendeg.android.swipelistview
to:
com.fortysevendeg.swipelistview
Missed files during the last package renaming.
Merge pull request #63 from ened/gradle

Gradle support & integration of the sample into one project
Fixes from #39 and API 7 compatibility.
Few lint warnings removed.
Merge https://github.com/ened/android-swipelistview
Fixed gradle buildToolsVersion value