[server] add debugging for Hooks & Operations (closes #2470048)

[dataimport] Add SQL Store for faster import - works ONLY with Postgres for now, as it requires "copy from" command - closes #2410822 This store will use: - copy from for massive insertions. - execute from for update. The API of this store is similar to the other stores.

[test] swap order in assert of `test_users_and_groups_non_readable_by_guests` unittest2 order is (expected, got), not the opposite. This help test report readbility.

[test] fix server/querier/build_descr1 test. There is no self.transaction of TestCase. I assumed the test writer meant a session. This seems to make the test pass.

[server] make `test_bfss_fs_importing_transparency` less verbose on failure Dumping the whole content of a file on failure is a bit annoying. We only print the bad version here (it's usually the file path).

[entity] drop redundant cache update This ``cw_attr_cache`` update is redundant, ``_cw_update_attr_cache`` already do this step.

[cw-ctl] silence msgcat and msgfmt (closes #2527594)

Added tag cubicweb-debian-version-3.15.7-1 for changeset c5400558f370

Added tag cubicweb-version-3.15.7 for changeset d8916cee7b70

prepare 3.15.7

[migration] fix crash when adding a new meta relation type. Closes #2532483

[ldapfeed] fix connection leak (closes #2532528)

[zmq] add an introductive docstring on ZMQComm

[server config] on quick start, system source is still activated. Closes #2535714

[web] use `inline` `Content-Disposition` by default (closes #2535734) since known time we have been serving static file with a `filename` parameter on the `Content-Disposition` header. But since d74addac92bb we explicitly serve file as attachment if a filename is provided. However this is valid to have `inline` disposition and `filename` parameter. This changeset revert this part of d74addac92bb, going back to `inlined` by default. `IDownloadable` code explicitly request `attachment` content to preserve expected behavior.

[web] allow configuration of the Content-disposition value The `set_content_type` function now takes and optional `disposition` parameter to control the value of this HTTP header. Use of `Content-disposition: inline` with a filename parameter are valid, so the presence of filename does not allows to choose between `attachment` and `inline`

[downloadable] fix filename HTTP header for simple name with space (closes #2535715) Since d74addac92bb, we export simple ascii filename without any encoding in the `filename` parameter of the `Content-Disposition` header. If this name contains space this will fails, the parameter value will be truncated at the space position. (eg. `filename=jungle babar.txt` read as `jungle`) We need to quote the filename to prevent this (eg. `filename="jungle babar.txt"`). Then literal quote and backslash needs to be escaped too. The new escaping is correct according this extensive test case data base: http://greenbytes.de/tech/tc2231/

merge fixes from stable

Added tag cubicweb-debian-version-3.15.6-1 for changeset b05e156b8fe7

Added tag cubicweb-version-3.15.6 for changeset 0163bd9f4880

prepare 3.15.6

[web] add a digital signature to error form (closes #2522526) Simple (and quite weak) implementation of a digital signature of the content to be submited by email in the error report view generated by ErrorView. The signature is a simple hmac hash computed using a secret key (generated at repository startup) and the "secret" form content to be included in the notification email. The controller can then check this content has not been modified or forged by a malicious user.

[web/views] bugfix: the mime type is text/plain, not text/txt (closes #2526345)

[doc] fix of personnal etc directory in book