This replaces boost::thread and most mutexes and condition variables with
std equivalents. It also adds support for std lock types to the strictest_lock
type trait.
This significantly, although not completely, reduces the dependency on
Boost.Thread.
Refs https://github.com/boostorg/log/issues/232.
The _SCL_SECURE_NO_WARNINGS, _SCL_SECURE_NO_DEPRECATE,
_CRT_SECURE_NO_WARNINGS and _CRT_SECURE_NO_DEPRECATE macros need to be
defined for every compiler that uses MSVC C/C++ runtime, so instead of
duplicating these definitions in multiple places, define them for
Windows platform regardless of the compiler. In particular, they are
now defined for clang-cl.
Some tests pull in pthread rwlock and therefore need _XOPEN_SOURCE=600
or higher to compile. Added platform defines to tests and examples
for good measure.
For MinGW worked around Boost.Build error when BOOST_LOG_WITHOUT_EVENT_LOG
is defined.
This allows to have different file names when actively writing the log file
and when rotating. In particular, this solves the problem with appending
to the previous file, when the log files are also collected and are supposed
to have distincs names.
