* fix(conan): conan-center used instead of bintray
* chore(doc): version updated to 21.04.1

REFS: MON-7244

* enh(doc): change doc layout
* enh(project): add license file

* test(perl): tests fixed to match last changes in clib.
* cleanup(cmake): cleanup of CMakeLists.txt

REFS: MON-6508

* enh(logger): add a common folder, for common sources.

* enh(perl): cleanup perl connector code.

* enh(ssh): cleanup code.

* enh(ssh): switch to spdlog.

* fix(chore): fix compile on centos7

* enh(perl): switch to gtest

* fix(perl): remove some dead code.

* enh(tests): switch to googletest.

* enh(log): add spdlog support for perl_connectors.

* fix(chore): use same connectors version for both connectos.

* fix(perl): fix compile

* cleanup(perl/checks): headers coding style

* cleanup(perl/orders): headers coding style

* cleanup(perl): headers coding style updated

* cleanup(perl/checks): c++ files coding style updated

* cleanup(perl/orders): c++ files coding style updated

* cleanup(perl): c++ files coding style updated

* fix(ssh): Failing tests compilation enabled.

* cleanup(ssh/checks): headers coding style updaed

* cleanup(ssh/orders): headers coding style updated

* cleanup(ssh/sessions): headers coding style updated

* cleanup(ssh): headers coding style updated

* cleanup(ssh/checks): c++ files coding style updated

* cleanup(ssh): c++ files coding style updated

* cleanup(ssh/orders): c++ files coding style updated

* cleanup(ssh/sessions): c++ files coding style updated

* cleanup(ssh/test/checks): c++ files coding style updated

* cleanup(tasks): classes inherited from tasks are updated to match clib

* cleanup(pipe_handle/buffer_handle): classes updated due to changes in clib::handle.

* fix(various): multiplexer is restored and listeners are cleanup

* cleanup(various): Many little changes

* fix(session): Deadlock fixed.

* cleanup(reporter): Not needed code removed.

* cleanup(orders/parser): unused code removed.

* cleanup(ssh/session): unused functions removed

* cleanup(parser/reporter): unused functions removed - changes due to handle_listener changes

* cleanup(gitignore): little update

* fix(perl): clib singletons api is changed.

* fix(ssh): clib singletons api changed

* fix(ssh/test/timeout): clib singletons api changed

* cleanup(ssh/test/orders): c++ files coding style updated

* fix(ssh/test/reporter): clib singletons api changed

* cleanup(ssh/test/credentials): c++ files coding style updated

* cleanup(benchmark): coding style updated

* fix(perl/options): unused code removed.

* enh(ssh): auto_ptr replaced by unique_ptr

* enh(ssh): concurrency::mutex replaced by std::mutex

* enh(connector): WIP to suppress concurrency objects from clib

The goal here is to use standard ones.

* enh(concurrency): Standard library used for threads stuff

* fix(test): Failing tests disabled

* cleanup(ssh): debug functions removed.

feat(perl,ssh): add --log-file option to connectors.

WEB-709 #to-test Discard session on I/O error.

This fixes #5797.