Easier debugging of syntax highlighters
Edit Book: Redesign the syntax highlighter to improve performance for large documents and extended editing sessions. Fixes #1314339 [edit book app "hangs" during edit session](https://bugs.launchpad.net/calibre/+bug/1314339)
Edit book: Make cursor movement smooth by not highlighting matching tags while the cursor is moving. Only match highlighting tags if the cursor stays still for a time.
Buffer file writes for large files (>10MB)
Merge branch 'master' of https://github.com/GRiker/calibre
Remove escaped EM tags, keeping only content

The source epub contains multiple escaped EM tags, also in title tags
and the table of contents. The safest way (and easiest way) to get a
readable epub from this is to dispense with the escaped EM tags
altogether, everywhere in .html and .ncx files (instead of replacing
them with unescaped ones), of course while keeping the human-readable
contents in place.
Merge pull request #237 from pft/nrcnex

Remove escaped EM tags, keeping only content
pep8
Smarten punctuation: Fix a double quote preceded by a hyphen at the end of a sentence (before the start of the next tag) being converted into an opening quote instead of closing quote. Fixes #1286477 [Smarten punctuation uses wrong character at end of paragraph](https://bugs.launchpad.net/calibre/+bug/1286477)
When deleting books from the calibre library, fix empty author folders not being deleted if they contain system generated cache files, like .DS_Store or Thumbs.db. Fixes #1313452 [[Enhancement] Delete author folders upon removal of only book](https://bugs.launchpad.net/calibre/+bug/1313452)
Use zero-based month as 2nd dynamic field in URL
Merge pull request #238 from pft/nrcnex

Use zero-based month as 2nd dynamic field in URL
Update Daily Mirror and Birmingham Evening Mail
DOCX Input: Fix formatting of the generated Index when the index is complex, i.e. with lots of references to the same item, multiple level of sub-items, etc.

Merge branch 'master' of https://github.com/pgarst/calibre
...
pep8
Edit book: Fix extra invalid entries being generated in the manifest when editing an AZW3 file that has no images.
Remove unused code
Fix #1315064 [locale 'C' prevents linux installation from completing](https://bugs.launchpad.net/calibre/+bug/1315064)
Adding security feed to list of feeds for Ars Technica