For extension content, transfer wrapper-token DSR to wrapped fragment.

* DSR was not being set on the expansion of this extension because
  it was not being transferred from wrapper tokens.

<source lang="bash">
git clone --recursive https://gerrit.wikimedia.org/r/pywikibot/core.git
</source>

* In turn, this caused dirty diffs after VE edits to this page:
  https://www.mediawiki.org/w/index.php?title=Manual:Pywikibot/Installation

  This patch fixes all of them (the remaining ones are semantic
  diffs because of off-by-1 DSR errors (investigated separately).

Change-Id: I60c1bd3bdf71681b39020f8454ef23557c370678
Bug fix in multi-line indent-pre (dont emit WS after </pre>)

* For this snippet, there was a trailing WS emitted after 'c'
  which led to an off-by-1 DSR error.
------
a
 b
 c
d
------

  In some scenarios, this caused selser to emit incorrect wikitext.
  For example, after trivial VE edits to this page:
  http://www.mediawiki.org/w/index.php?title=Manual:Pywikibot/Installation

* TODO: Need to figure out how to add a test for this since our
  test comparison script normalizes whitespace.

Change-Id: Ic5ff3c3be416e9c70f0eb04229a8be3d97bd3d16
Merge "For extension content, transfer wrapper-token DSR to wrapped fragment."
Merge "Bug fix in multi-line indent-pre (dont emit WS after </pre>)"