Mobile feature list and user_session_id (usi) support

Add crash to mobile feature list and send to Instana backend
Add user_session_id (usi) to beacons

Fix issue for setCaptureHeaders method not capture http response headers

1.6.4

Fix issue for setCaptureHeaders method not capture http response header

Fix duplicated beacons issue

1.6.3

Fix duplicated beacons issue

Slow sending mode improvement

• Once in slow sending mode, periodically send 1 beacon. Once out of slow sending mode, flush all beacons immediately.
• [Tech Preview] Add sample code in InstanaAgentExample app to show how to enable crash reporting to Instana backend.

Improve retry mechanism and Fix concurrent issue with MetaData

• Fix crash caused by appendMetaData() inside InstanaProperties class
• Improve error handling on beacon send failure, now we have a new setup option slowSendInterval to slow down retrying on network issue.

Refactor code and add more unit test cases

1.6.0

Bump 1.6.0

Improve thread safety for collections

Add new atomic types for some collections by @tapwork in #35

Full Changelog: 1.5.1...1.5.2

Capture HTTP header fields

• Add new feature to capture HTTP header fields by providing an array of NSRegularExpression

Add redaction for HTTP query parameters

• Add new feature to redact password, key, secrets from HTTP query parameters
• Improve thread safety

Updated authentication challenge method handling

Implement task-based authentication challenge method and forward to session-based if needed