This updates Boost, libevent, ccache and dbus to their latest versions.
ZeroMQ will also be updated, but is currently held up by a Windows build issue, see #9254.
Qt/other build system changes will be PR'd separately.
Will update #8639 once this is merged.
libevent 2.18-stable
libevent 2.1.8-stable, contains openssl fixes for resetting fd and using bufferevent_openssl_filter_new(). vagrant fixes, some build fixes, increased timeout for some tests (to reduce number of failures due to timing issues), date in RFC1123 format and running tests in parallel.
Boost 1.64.0
Switch away from SourceForge for the download.
ccache 3.3.4
Changelog:
Documented the different cache statistics counters.
Fixed a regression in ccache 3.3 related to potentially bad content of dependency files when compiling identical source code but with different source paths. This was only partially fixed in 3.3.2 and reverts the new “Names of included files are no longer included in the hash of the compiler’s preprocessed output” feature in 3.3.
Corrected statistics counter for -optf/--options-file failure.
Fixed undefined behaviour warnings in ccache found by -fsanitize=undefined.
