dscanner - Drozer based post-build dynamic vulnerability scanner command

dscanner - Drozer based post-build dynamic vulnerability scanner command

 * New command `dscanner`, enables one to scan signed APKs with Drozer
 * Drozer is a dynamic vulnerability scanner for Android
 * Drozer runs in a emulator or on-device, this new `dscanner` command...
  * starts a docker image with Drozer and the Android Emulator pre-installed,
  * loads the signed APK into the emulator
  * activates Drozer automated tests for the APK
  * gathers the report output and places it next to the original APK
 * The Drozer docker image can be:
  * cached locally for re-use (just don't run --clean*)
  * retrieved from dockerhub.com for more efficient runtime
  * or be built from scratch (in the new "./docker" directory)
 * New "Vulnerability Scanning" documentation section (run gendocs.sh)