[entity] improve error message

[doc] fix doc and tutorials about hooks and operations

[optim] cache rset column structures When iterating over large resultsets (lot of colcumns, lot of lines) to build entities, caching column structure (which attribute or relation is stored in each column) can improve performance noticeably.

[js] make _loadAjaxHtmlHead aware of mod_concat-like urls _loadAjaxHtmlHead keeps track of already imported resources (js / css) to make sure they're not included twice, but with mod_concat-like urls, things get a bit more complicated : if BASE_URL/data??foo.js,bar.js is already imported, then loading : BASE_URL/data??bar.js,spam.js should only load spam.js

[etwist] in debug-mode, concat-file is rebuilt if one of the concatenated file is more recent

[facets] display splash image while facets are reloading content (closes #1624851)

[facets] mark titles of active facets with red dot (closes #1624857)

[facet] add missing selector to HasRelationFacet

[facets] proper fix for #1625112: we should rather call unicode() as we always manipulate string as unicode internally

merge

[etwist] Generates apache's mod_concat-like urls for js and css Uses the lists of js, css and ie_css included in order to generate urls compatible with Apache mod_concat (ie: http://test.fr/??file1.js,file2.js). Css files may use `media` option or may be for IE only ; this patch does not concatenate css filenames for different media types or different IE specs. It concatenates only files served under cubicweb's `data` urls and keeps original include order. The generated urls are added to the HTML header as usual. HOW-TO: - calling HTMLHead(datadir_url) will enable the url concatenation - calling HTMLHead() will not benefit of url concatenation IMPORTANT NOTE: - fckeditor can no more be served under `/data/` segment

handle js/ css file concatenation with twisted