* DirCacheCheckoutTest: Open Git and TreeWalk in try-with-resource
* CommitCommand: Remove declaration of unthrown exception
* Branch: Fix variable hiding warning
* ApplyCommandTest: Open Git in try-with-resource
* PackFileTest: Open ObjectInserter.Formatter in try-with-resource
* Simplify size test in PackWriter
* Declare critical exposed methods of ObjectToPack final
* Declare internal flag accessors of ObjectToPack final
* Remove unused method isDeltaAttempted()
* Simplify setDoNotDelta() to always set the flag