Special commit to update erp5-doc revision after change of BT path.

BT were moved into bt5/ subdirectory in
nexedi/erp5-doc@3996ae1f

This reverts commit dcd2f8d6.

It has to be redone with proper test coverage.

This reverts commit 04ea0535.

It has to be redone with proper test coverage.

Since the introduction of shared parts, there is no guarantee about
the location of sqlite3 binary.

Calling makeModuleSetUpAndTestCaseClass results already with preparing some
environment and also test classes will run the promises, so they would never
execute test_kvm_sanity_check.

So create a method sanityCheck to check the environment and depending of the
result call or not makeModuleSetUpAndTestCaseClass and skipIf test cases
when environment is not sane enough.

Also drop now needless etc/promise directory.

As possible cover promises in tests.