Ebookmaker

- added 'x-ebookmaker' class to epub body elements. There are now 4 "x-ebookmaker" classes
- css can now apply styles that are triggered by being a descendent of .x-ebookmaker. This addition is meant to replace the 'handheld' media query that is deprecated in HTML 5
- the 'x-ebookmaker-important' class on on image element tells ebookmaker not to remove the image, even in no-images builds.
- the 'x-ebookmaker-drop' class tells ebookmaker to remove an element and its descendents from ebook builds.
- the 'x-ebookmaker-pageno' class is applied to some span elements whose content has been stripped because they use a class that indicates they represent page numbers: pagenum pageno page pb folionum foliono
- added mayan as a language not supported by kindlegen
- typos fixed in README - thanks Joseph Koshy

- fixed minor issue where the spider was getting confused when iterating on WrapperParsers.

- handle invalid quantization table in jpeg files when using quality 'keep'
- respect rel="nofollow" attribute: this allows authors to link to an alternate version file in html without duplicating content in the EPUB file.
- set wrappers to nonlinear in spine.
- fixed bugs and ugliness in toc generation
- when the same header level is consecutive, only one toc item is generated. (We see this used to make multiline heads or titles)
- toc normalization made a hash of the toc. Now the toc is normalized in the epubwriter, not in the parser.
- add display:block to standard css sheet to prevent hidden headings from breaking kindlegen
- added a configuration option to use calibre (or whatever!) for non-supported in kindleget languages.

- Fix reversion in 0.9.2 which caused CoverWriter in EbookConverter to fail. (It uses ImageParser to convert images from PNG to JPEG
- add a test to check this

- note that EbookMaker is no longer installable in Python 2.7 (thanks cpeel)
- clean up pipfile and gitignore pipfile.lock (thanks cpeel)
- fixed bug where filepaths need escape in HTML
- fixed issue where compression was expanding compressed jpegs (thanks choward)
- adde EBOK flag in MOBI when using ebook-convert (thanks rfrank)

Minor bug fix and optimization.
- picsdir builds weren't recognizing when it was copying files to themselves
- "broken" images are now inserted when an image is missing
- title attribute in wrappers needed escaping
- build times are now reported to logs
- small optimization with preparse on image parsers