Merge branch 'master' into stable-5.4

Merge branch 'master' into stable-5.4

* master:
  Handle missing "ours" stage in WorkingTreeIterator.hasCrLfInIndex()
  Config: Add helper method to check for empty value
  ErrorProne: Increase severity of FutureReturnValueIgnored to ERROR
  FS_Win32: Add missing parentheses on if-blocks
  Upgrade spotbugs to 3.1.12
  Abbreviated{Long}ObjectId: Make operator precedence explicit
  GC: Update TODO comments
  FS_POSIX: Fix reference comparison of Boolean.FALSE
  Increase bazel timeout for long running tests
  Use bazelisk to switch between used bazel version
  Bump minimum Bazel version to 0.26.1
  Bazel: Bump skylib library version to 0.8.0
  Retry loading config when locked by another process
  Make pull --rebase on an unborn branch do a checkout
  Warn if configured cookie file is missing
  Handle escaped CR-LF in git config files
  DescribeCommand: use glob match instead of path match
  Fix off-by-one error in RebaseTodoFile when reading a todo file
  Consistently use "!isEmpty()" to detect non-empty list
  TransportHttp: Check for non-empty list with "!isEmpty()" rather than
    "size() > 0"
  TransportHttp: Fix comparison of size with ">= 0"
  NetscapeCookieFileTest: Split HttpCookiesMatcher to own class
  Bazel: Add missing dependency on mockito for TransportHttpTest
  Determine hard-linking and nlink support per FileStore
  Support reading and writing cookies.
  Repository: Add getIdentifier() method to avoid instanceof operator
  Update to Orbit R20190602212107
  PacketLineIn: Deprecate the END constant
  PacketLineIn: Add an iterator over strings in the input stream
  Replace most usages of PacketLineIn.END with PacketLineIn.end()
  PacketLineIn: Deprecate DELIM constant
  Replace trivial reference comparison of PacketLineIn.{DELIM,END}
  PacketLineIn: Rename isDelim to isDelimiter
  ProtocolV2ParserTest: Fix typo in comment
  Upgrade Bouncy Castle to 1.61
  Update to Orbit R20190531194818 and rollback update to Ant 1.10.6
  cli: Add the --always option to describe
  DescribeCommand: Support the "always" option
  cli: Add the --tags option to describe
  DescribeCommand: Consistenly omit the default value
  Remove excess blank line in FileUtilsTest
  PacketLineIn: Add helper methods to check for END and DELIM
  UploadPackTest: Rename variable to avoid hiding class member
  UploadPackTest: Add missing <> operator on instantiation of ArrayList
  BitmapCalculator: javadoc fixes
  RevWalkUtils: add progress callback to findBranchesReachableFrom
  Upgrade maven-source-plugin to 3.1.0
  Upgrade maven-jar-plugin to 3.1.2
  Upgrade jacoco-maven-plugin to 0.8.4
  BitmapCalculator and its test: add missing license header
  RevWalk: new method createReachabilityChecker()

Change-Id: I4d76c7c0dbe6411c842f3468b709f7df51789c08
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>