v1.15.1 - ASIO updated

The main point of this release is so I can make a DOI via Zenodo.

The CHANGELOG is just a copy-paste from the commit history. Most changes by @tstenner:

• Fix several compiler and clang-tidy warnings
• Unit tests: fix off-by-one error in last_error test. Many thanks to @tobiasherzke
• Fix loguru thread-local storage for MinGW
• Test thread-local storage in loguru library
• Move (static) thread local last_error buffer into lsl_last_error func
• Update link to conda package
• Use alias for asio namespace
• Determine removed BOOST_BYTE_ORDER in sample.h
• Replace deprecated Boost.Asio classes
• Update asio subset
• Use namespace alias for asio, avoid copying error_code in handlers
• Move UUID generation to streaminfo, add UUID format unit test
• Move utility classes to util/ subdirectory
• Fix version, otherwise liblsl_VERSION_PATCH is undefined
• Update standalone_compilation_linux.sh
• Replace Boost.UUID with a simple UUID4 generator
• Add missing include needed for Windows MSVC 2019
• Fix protocol incompatibility introduced in 6e0070c. …
• Apply formatting to examples