Log Message:
Updated packate to the latest version, 5.0.0. Changes include:

===== 5.0 (2016-01-28) =====

* Add Eliom_shared and server-side Eliom_content.{Html5,Svg}.R modules
* Add PPX syntax extension
* Clean-up form APIs, now available under Eliom_content.Html5.{D,F}.Form
* Patches to significantly reduce the size of request data
* Compatibility with TyXML 3.6, Js_of_ocaml 2.7, and reactiveData 0.2
* Various bugfixes and enhancements

===== 4.2 (2015-07-21) =====

* Add Manip.children, to get the html children of an element.
* Simplify Html5 and Svg signatures using tyxml's signature functors.
* Various logging improvements, in particular in Eliom_client.
* Fix eliomdep's exit code when calling option "-sort".
* Fix #168: call_ocaml_service always sends boolean true.
* Makes server function return types covariant.
* Restore compatibility with ocsigenserver 2.6 and lwt 2.4.7.
* Various bugfixes and wiki updates.