Revert "CompositeException does not mutate nested exceptions by attaching stacks, but instead"

This reverts commit f4ae92aa624923e9a632fb677730a2d6e04595e5.
Remove cycles in CompositeException
Move cast to parent function
Remove cast
Remove unused imports/locals
Add generics
Add generics
Correct static access warnings
Merge Perf Fix: Re-enable fast-path
Merge pull request #1462 from benjchristensen/merge-perf-fix

Merge Perf Fix: Re-enable fast-path
Merge Bug: Missing Emissions

Notes and temporary fix
Merge pull request #1463 from benjchristensen/merge-1420

Merge Bug: Missing Emissions
[Gradle Release Plugin] - pre tag commit:  '0.20.0-RC2'.
[Gradle Release Plugin] - new version commit:  '0.20.0-RC3-SNAPSHOT'.
Version 0.20.0-RC2
Update CHANGES.md
Merge pull request #1436 from gliptak/genericswarnings

Correct warnings
Merge pull request #1431 from tomrozb/composite-exception

CompositeException fix for Android