Fix violations for Squiz.Commenting.DocCommentAlignment.SpaceBeforeTag

Conflicts:
	inc/parser/xhtml.php

Fix violations for Generic.PHP.LowerCaseConstant.Found

Michael Hamann commented in pull request #306 that phpseclib has not
been adopted by the DokuWiki project. Therefore, the changes made to
reduce the CodeSniffer violations should be reverted and the local copy
of phpseclib should be excluded from CS checks. This commit reverts the
previous changes and adds the appropriate exclusion rule.

Change indentation to ensure code confirms to CodeSniffer rules.

Remove whitespace from end of lines to reduce the number of CodeSniffer
violations.

This adds the parameter extraction code from the xhtml renderer to the
metadata renderer in order to not to include the parameters in the id
that is recorded as link target. A test case checks that the link is
actually returned as backlink (fails without the fix).