Measure Detector Integration and Password Authentication

• Integrate with measure detector API.
• Authentication for password protected IIIF manifests.

What's Changed

• Upgrade to download images from iiif manifest by @hizclick in #25
• Update android version by @hizclick in #26
• Feature upgrade to android 9 by @hizclick in #24

Full Changelog: v3.0.1...v4.0.0