Introduces a conanfile.py (and a Conan recipe for RocksDB) to enable building the package with Conan, choosing more recent default versions of dependencies. It removes almost all of the CMake build files related to dependencies, and the configurations for Travis CI and GitLab CI. A new set of cross-platform build instructions are written in BUILD.md.
Includes example GitHub Actions workflow for each of Linux, macOS, Windows.
* Test on macos-12
We use the <concepts> library which was not added to Apple Clang until
version 13.1.6. The default Clang on macos-11 (the sometimes current
version of macos-latest) is 13.0.0, and the default Clang on macos-12 is
14.0.0.
Closes#4223.
This patch removes calls to several deprecated asio functions.
* `io_service::post` becomes `post` (free function)
* `io_service::work` becomes `executor_work_guard`
* `io_service::wrap` becomes `bind_executor`
* `get_io_context` becomes `get_executor` or `get_executor().context()`
This patch was tested with boost 1.69 and 1.70. The functions
`ripple::get_lowest_layer` and `beast::create_waitable_timer` are required to
handle a breaking difference between these versions. When rippled no longer
needs to support pre 1.70 boost versions, both of these functions may be
removed, and the waitable timer injections may also be removed.
