HTML reader:  Generalized table parser.

This commit doesn't change the present behavior at all, but
it will make it easier to support non-simple tables in the future.
HTML reader:  Handle non-simple tables (#893).

Column widths are divided equally.

TODO:  Get column widths from col tags if present.
HTML reader: read widths from col tags if present.

Closes #893.
Text.Pandoc.ImageSize:  Handle EPS.

Closes #903.  This change will make EPS images properly sized
on conversion to Word.
LaTeX/Beamer template: Added `classoption` variable.

This is intended for class options like `oneside`; it may
be repeated with different options.  Thanks to Oliver Matthews.
Added `ignore_line_breaks` markdown extension.

This causes intra-paragraph line breaks to be ignored,
rather than being treated as hard line breaks or spaces.
This is useful for some East Asian languages, where spaces
aren't used between words, but text is separated into lines
for readability.
Improved fetching of external resources.

* In Shared, openURL and fetchItem now return an Either, for
  better error handling. (API change.)
* Better error message when fetching a URL fails with
  `--self-contained`.
* EPUB writer: If resource not found, skip it, as in Docx writer.
* Closes #916.
Fixed warning.
Text.Pandoc.PDF:  put temporary output directory in TEXINPUTS.

This will help later when we try to download external resources.
We can put them in the temp directory.  See #917.
README: Fix minor typo
Merge pull request #924 from drothlis/patch-1

README: Fix minor typo
LaTeX template: Added `biblio-style` variable.

Closes #920.
Added info about CABALDIR.

Modified from a patch by achalddave.
PDF generation improvements.

* `Text.Pandoc.PDF` exports `makePDF` instead of `tex2pdf`.
  (API change.)
* `makePDF` walks the pandoc AST and checks for the existence of
  images in the local directory.  If they are not found, it attempts
  to find them, either in the directory containing the first source
  file, or at an absolute URL, or at a URL relative to the base URL
  of the first command line argument.
* Closes #917.
Markdown reader: Improved strong/emph parsing.

Using technique from github.com/jgm/Markdown.

The new parsing algorithm requires no backtracking, and no keeping
track of nesting levels.

It will give different results in some edge cases but should not
affect most people.
LaTeX reader:  Don't add spurious ", " to citation suffixes.

This is added when needed in Text.Pandoc.Biblio anyway.
Biblio:  Tweaks to improve default behavior.

* A suffix beginning with a digit gets 'p' inserted before it
  before passing to citeproc-hs, so that bare numbers are treated
  as page numbers by default.
* A suffix not beginning with punctuation has a space added at
  the beginning (rather than a comma and space, as was done before).
* This adding occurs not just in author-in-text citations, but in
  all citations.

The result of these changes (and the last commit) is that
`\citep[23]{item1}` in LaTeX will be interpreted properly,
with '23' treated as a locator of type 'page'.
Require highlighting-kate 0.5.5.

0.5.4 has a serious memory leak that affects the mandoc parser.
See highlighting-kate#34.
Merge branch 'master' of https://github.com/jgm/pandoc