More robust trim-url function that strips initial "www." (without preceding "http://") and trailing forward slashes.
Merge pull request #159 from oreillymedia/urls

More robust URL-compare function
New <?prev_url?>, <?next_url?>, and <?toc_url?> PIs for inserting just a URL, rather than a full <a>.
Escaped version of <?prev_url?>, <?next_url?>, and <?toc_url?> for use in href attrs.
Merge pull request #161 from oreillymedia/urls

New PIs for inserting prev, next, and TOC URLs
Adding xref-pagenum-style template for generating data-xref-pagenum-style attr values.
@data-xref-pagenum-style handling for XREFs.
Handling for data-xref-pagenum-style attributes for index entry generation.
Toggle data-xref-pagenum-style attr with autogenerate.xref.pagenum param for XREFs.
Renaming param for clarity.
Handling in chunk.xsl for data-xref-pagenum-style attrs.
Updated comment.
Merge pull request #163 from oreillymedia/xref-pagenum-style

Adding support for "pagenum" style functionality
Refactoring and bug fix (for lower-level sections) for xref-pagenum-style template.
Merge branch 'xref-pagenum-style'
Fixing formatting errors.