Merge branch 'stable-4.2'

Merge branch 'stable-4.2'

* stable-4.2:
  Don't use deprecated LockFile constructor
  Fix warnings about unchecked conversion of MergeResult
  MockServletConfig: Fix warning about unchecked conversion of Enumeration
  HugeFileTest: Make Git a class member and open in try-with-resource
  Suppress "unchecked cast" warnings related to UploadPackFactory.DISABLED
  DiffAlgorithms: Fix warnings about variable hiding
  DirCacheBasicTest: Open ObjectInserter.Formatter in try-with-resource
  DirCacheBuilderIteratorTest: Open TreeWalk in try-with-resource
  DirCacheCGitCompatabilityTest: Open TreeWalk in try-with-resource
  DirCacheCheckoutMaliciousPathTest: Open Git and RevWalk in t-w-r
  DirCacheIteratorTest: Open TreeWalk instances in try-with-resource
  ForPathTest: Open TreeWalk in try-with-resource
  GitConstructionTest: Open Git instance in try-with-resource
  IndexDiffTest: Open Git instances in try-with-resources
  ManifestParserTest: Don't use deprecated StringBufferInputStream
  InMemoryRepository: Remove unused RevWalk from batch method signature
  IndexModificationTimesTest: Open Git instances in try-with-resource
  InterIndexDiffFilterTest: Open TreeWalk in try-with-resource
  LockFileTest: Open Git instance in try-with-resource
  JGit v4.1.2.201602141800-r
  MergeCommandTest: Use JUnit's assume to check preconditions
  MergeCommandTest: Open Git instances in try-with-resource

Change-Id: Ie5dba6b9132a29e86958a04fa2b76465bcd2c6b5
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>