tests/test-generaldelta.t

run-tests: move diff generation into TestResult

TestResult is the thing that captures all our test results. It's logical
for diff viewing to be handled there and not inside Test.

While writing this patch, it was discovered that Test.fail() was
printing redundant test result output. This has been removed.

Arguments controlling diffs have been removed from Test.__init__.

Check whether size of generaldelta revlog is not bigger than its
regular equivalent. Test would fail if generaldelta was naive
implementation of parentdelta: third manifest revision would be fully
inserted due to big distance from its paren revision (zero).

  $ hg init repo
  $ cd repo
  $ echo foo > foo
  $ echo bar > bar
  $ hg commit -q -Am boo
  $ hg clone --pull . ../gdrepo -q --config format.generaldelta=yes
  $ for r in 1 2 3; do
  >   echo $r > foo
  >   hg commit -q -m $r
  >   hg up -q -r 0
  >   hg pull . -q -r $r -R ../gdrepo
  > done

  $ cd ..
  >>> import os
  >>> regsize = os.stat("repo/.hg/store/00manifest.i").st_size
  >>> gdsize = os.stat("gdrepo/.hg/store/00manifest.i").st_size
  >>> if regsize < gdsize:
  ...     print 'generaldata increased size of manifest'