Merge branch 'cq-diff'

Per CQ 3559 "JGit - Eugene Myers O(ND) difference algorithm" we
have approval to check this into our master branch.

* cq-diff:
  Add file content merge algorithm
  Add performance tests for MyersDiff
  Add javadoc comments, remove unused code, shift comments to correct place
  Fixed MyersDiff to be able to handle more than 100k
  Fix some warnings regarding unnecessary imports and accessing static methods
  Add the "jgit diff" command
  Prepare RawText for diff-index and diff-files
  Add a test class for Myers' diff algorithm
  Add Myers' algorithm to generate diff scripts
  Add set to IntList

Conflicts:
	org.eclipse.jgit/src/org/eclipse/jgit/diff/RawText.java

Change-Id: Ia8e98d81ba1ab52f84d0258a40e6ef5eece9a5b1
CC: Christian Halstrick <christian.halstrick@sap.com>