Configuration parameter for alternative scan folder

[gilfernandes]

It would be nice to have some configuration option which allows to scan and extract resource strings from another directory besides the default directory.

This pull request allows to specify a different directory on which the scan is supposed to happen. With the changes introduced in this pull request you include in your build.gradle file your classpath declaration:

classpath 'de.ito.gradle.plugin:android-string-extractor:0.1.1'

and then for scanning the app folder (as an example) you can add this configuration to your build.gradle file:

stringExtractionProperties {
    targetFolder = 'app'
}

[ankit1057]

Seems appropriate to me.