Merge branch 'delta'

Merge branch 'delta'

* delta: (103 commits)
  Discard the uncompressed delta as soon as its compressed
  Honor pack.windowlimit to cap memory usage during packing
  Honor pack.threads and perform delta search in parallel
  Cache small deltas during packing
  Implement delta generation during packing
  debug-show-packdelta:  Dump a pack delta to the console
  Initial pack format delta generator
  Add debugging toString() method to ObjectToPack
  Make ObjectToPack clearReuseAsIs signal available to subclasses
  Correctly classify the compressing objects phase
  Refactor ObjectToPack's delta depth setting
  Configure core.bigFileThreshold into PackWriter
  Add doNotDelta flag to ObjectToPack
  Add more configuration options to PackWriter
  Save object path hash codes during packing
  Add path hash code to ObjectWalk
  Add getObjectSize to ObjectReader
  Allow TemporaryBuffer.Heap to allocate smaller than 8 KiB
  Define a constant for 127 in DeltaEncoder
  Cap delta copy instructions at 64k
  ...

Conflicts:
	org.eclipse.jgit.pgm/src/org/eclipse/jgit/pgm/Diff.java
	org.eclipse.jgit/resources/org/eclipse/jgit/JGitText.properties
	org.eclipse.jgit/src/org/eclipse/jgit/JGitText.java
	org.eclipse.jgit/src/org/eclipse/jgit/revwalk/RewriteTreeFilter.java

Change-Id: I7c7a05e443a48d32c836173a409ee7d340c70796