Properly find Valgrind on OpenSUSE

CI: remove redundant CMake param in Windows build

Introduce flat transaction class and change containers' behavior

and make sure to skip only Valgrind tests, not for all tracers.

And update check in run-build.sh to test if build really fails.

major CI/utils cleanup

ref. 02c0feca

and make sure WORKDIR env is set.

it's useful for debugging, especially if tests fail.

Pushing image happens only on push events so tests are expected to pass.
Taking this into account - pushing can be done right after rebuilding
an image, instead of marking a flag for a later push.

- set proper IMG_VER on stable branches,
- use "rebuild" param (for pull-or-rebuild.sh) on stable branches.

rather than hardcoded address string.

and remove ndctl installation step in CentOS, since it's installed from package.

and use it in jobs not requiring image rebuilding.

instead of using array of hard-coded dir names.

fixes warning in log: 'Unable to find image '...' locally'.

so we don't have to update this piece of code every release.

and let other OSes build independently.

to make possible to override it for testing on real pmem. Default: ON.

to avoid warnings in build logs.

in run-doc-update.sh created PRs.

and additional minor cleanups in run-doc-update.sh

and don't build docs.

- tidy up workflow files,
- make scripts more verbose,
- unify printed messages,
- use proper ${} bash variables syntax,
- order code,
- remove redundant code.

Merge stable-1.11 into master

and changing containers' transactional methods behavior.

They will work after introducing flat_transaction.

Rename pmem::obj::transaction to pmem::obj::basic_transaction
and make transaction a macro.

The common code between basic_transaction and flat_transaction
is moved to a base class. All the doxygen comments are placed
next to the actual transaction implementation.

modify slice to work with output iterators

radix_tree: fix use after free