Passed every png file through http://www.smushit.com/ysmush.it/ saving some 1-2kb of binary image data

Icon downloaded from http://forum.skype.com/style_emoticons/skype/skype.png

I asked someone internally for file copyright and answer was ok (do
whatever you want)

A page could have possibly hundreds of backlinks, when the cache is
outdated they should not be rererendered at once

Quoted-Printable specifies a maximum line length and some mail tools
(Apple mail and Thunderbird) take this quite serious and will fail to
decode subjects encoded with quoted-printable when the subject exceeds
the length limit.

The correct fix would be to wrap the header into multiple lines. But
this seems not to be possible with mails() $subject variable.

This patch switches to Base64 encoding for long subjects.

A general decision if switching completely to Base64 is the best way
to go is still open. (see bugreport)

All linebreaks before p_close have been removed.

This fixes a PCRE backtrack error that occurred on large pages like
:users on dokuwiki.org.

This research suggests that, the change does not help, but in fact
breaks previoulsy working setups:
https://bugs.dokuwiki.org/index.php?do=details&task_id=1755#comment3446

I'm still at loss on how to fix this bug.

This reverts commit 2ae68f97.

Anika's merge did not pul in the individual patches as one would expect.

Then I messed up when trying to fix this by merging with danny's repo
again but used the wrong branch. So we're still missing two patches. To
have them apply cleanly I have to revert Anika's merge here. Another
merge for the missing two patches will follow.

This reverts commit b17e20ac.

A search equivalent to a new ID so it should show up in the bread
crumbs.

This makes it possible to find words that include soft-hyphens. However,
search higlighting will not work and I have no idea how to make it work.

There is no reason why the subscription should wait for other calls
because the lock is only for one page so once the other call has
finished the work has already been done. This simplifies the lock
mechanism so there is no more loop.