[cubicweb] #344957 : fix popup display in IE7

<a> doesn't have alt attribute

fix so that entity's summary appears in main content cell to avoid layout pb

merge

ease overriding of copy warning

merge

avoid installing editor n times for n ajax loads

consider CW_MODE='system', the opposite of 'user' (eg use 'installed' mode while using the forest)

prepare 3.4.6

generic rtag cleaing method

fix necessary for some tests

[vreg] keep positional arg compat

check object has __registry__ attribute before call to register()

provide facility to override main header components without having to override the whole methode

reorganize, add some docstring an format_field/format_section convenience methods

oops

backport stable

merge

translate bits of the doc

fix __cmp__ arguments

backport stable

fix potential session cache effect: entity's rset may have been emptied

oops

force cache clear when external entity is edited, we don't know what may occurs in external repository hooks

[multi-sources] enhance relation'source detection to avoid inconsistency

[multi-sources] new may_cross_relation method on sources

[multi-sources] move [dont_]cross_relations to AbstractSource

[multi-sources] in ms config, don't try to delete previous state in some condition

[multi-sources] in ms config we don't have state_of (and probably others, but that's the one used until now...)

[pdf] remove buggy css, add alt to img for valid xhtml