Ability to specify new file name

[rastikw]

Name of a new (non-existing) file name can be specified, e.g. when the file should be created by the app. This is presented to the user as additional menu item and has to be activated:
intent.putExtra(FilePickerActivity.EXTRA_ALLOW_CREATE_FILE, true);

[rastikw]

Check build failed because I've changed signatures of some of the methods.

[spacecowboy]

Thanks for the PR!

This is already in progress. I'm thinking about different ways to expose this to users. See #83 for images and such. I'd appreciate feedback, your approach is another way to go of course.

[spacecowboy]

Closing as I have just released 3.0.0 which includes this functionality.

[rastikw]

Great, thank you. I've updated my code to use version 3 and discarded my changes to the lib.