Html5 : Make it possible to specify the position of a figcaption.

fix #6
HTML5 : Make a_input_max and a_input_min take floats.
Use -annot and -bin-annot only if the major version of the current ocaml compiler is 4
Allow attribute required for select elements
Use List.append instead of @ in syntax extension
Optional argument for HTML5 attribute a_step
Merge pull request #13 from benozol/step-option

Minor improvements (and option for a_step)
Fix ocamlduce detection, check versions
Merge pull request #18 from hhugo/duce

Fix ocamlduce detection, check versions
handle number entities
handle CDATA
Merge pull request #20 from hhugo/cdata

handle CDATA
Merge pull request #19 from hhugo/entities

handle number entities
trigger buildbot
Make the SVG sigs wrappable in a monad.
Make the html wrappable in a monad.
Tying up the knot in order to makes everything work with the wrapping monad.

The wraping monad is now in a separate module. The Xml module contains
only the type 'a wrap. Functors in Html_f and Svg_f are specialized
accordingly. Each functor have a partialy applied version against the
empty monad.
Add documentation for the functorial interface of tyxml.
Add a short documentation for MakeWrapped functors in the .mli.
Whitespace changes, to fix the damages done by regexs.