Adding feature of installing Debian in /data/debian location directly without creating img file

* Modifying the shell scripts
* adding option in the Preference
* adding NativeHelper.isInstalled() function
* updating the media mounted and unmounted Receiver
moving to cdebootstrap v0.6.2 from v0.6.1
replacing image_path with install_path

After adding feature 'Install on Internal Storage' the install_path name seams to be relevant,
as it can be a directory while install in Internal storage.