erp5_barcode: update XML and migrate property sheets
runUnitTest: remove obsolete code for "static" files now that everything has moved to ZODB
erp5_sso_openam: update XML and migrate property sheets
BT: read metadata (bt/* files) through BusinessTemplateArchive
wip
BT: let BusinessTemplateFolder walk inside directory tree recursively
BT: don't export 'revision' anymore

Because on DVCS with branches, history is not always linear, we must stop
using increasing integer for revisions because they cause too many conflicts
and a higher revision number does not necessarily means the a BT newer.
They're now a cryptographic hash of all the contents of the Business Template,
and they're computed automatically:
- by genbt5list
- at download
- at building (by default)
- at export

Of course, 'only_newer' parameter in updateBusinessTemplateFromUrl becomes
really misnamed.