fix _cubes dir

handle nicely typical installation other than debian package / mercurial forest * new _find_prefix method to detect installation prefix (maybe specified using CW_INSTALL_PREFIX environment variable) * set various resource accessors according to this, cleanup on the way * remove no more necessary APYCOT_ROOT hacks

When a TC failed to initiliase the database, the following test are SKIPPED When a TC failed to initiliase the database, the other test of the same TestCase are skipped with an explicite message instead of failing later for with an unrelated message.

[c-c] new server_maintenance hook, called on c-c shell / upgrade

[appobject] add version number to deprecation warning

update rql dependency

backport stable

fix migration script

[cleanup] useless try except

[source storage] refactor source sql generation and results handling to allow repository side callbacks for instance with the BytesFileSystemStorage, before this change: * fspath, _fsopen function were stored procedures executed on the database -> files had to be available both on the repository *and* the database host * we needed implementation for each handled database Now, those function are python callbacks executed when necessary on the repository side, on data comming from the database. The litle cons are: * you can't do anymore restriction on mapped attributes * you can't write queries which will return in the same rset column some mapped attributes (or not mapped the same way) / some not This seems much acceptable since: * it's much more easy to handle when you start having the db on another host than the repo * BFSS works seemlessly on any backend now * you don't bother that much about the cons (at least in the bfss case): you usually don't do any restriction on Bytes... Bonus points: BFSS is more efficient (no queries under the cover as it was done in the registered procedure) and we have a much nicer/efficient fspath implementation. IMO, that rocks :D

[bfss] fix name error

[source storage] on deletion, entity has no edited_attributes

[cleanup] rename dbms_helper to dbhelper for consistency

[entity] we also have to override dict.pop to properly maintain edited_attributes consistency

[bfss test] some minor refactoring. Test deletion + creation/update/deletion rollback