[book] add autoload section from code and fix sphinx warnings * drop misleading faq entry since clear explanation can be found in internationalization chapter * use autodata sphinx directive instead of raw text * fill empty chapter with autodoc: - devweb/httpcaching.rst - devweb/resource.rst - devweb/views/idownloadable.rst - devweb/views/wdoc.rst * use shebang in excerpt to denote shell code * fix some bad indented docstrings in javascript files

[controller] fix wrong view name when error occurs in UndoController

[datafeed] renaming parser attribute to parser_id makes things clearer

cleanup and assert we don't import unexpected stuff

[source config] fix synchronization on configuration entity changes

[ui, sources] configure source form: hide synchronizing and mapping entities, use simple text input for parser

[rql annotation] fix bad invariant variable w/ has_text relation: this is only true when has_text will be used as principal (though we don't know that yet)

[test] update to new db handler api

[querier] turn remove_clauses/restore_clauses into a context manager

[devtools pg handler] some fixes so we get proper error when pg host is not reachable