Chrono: merge from trunk 1.54.
Chrono: merge doc to fix #8370.
Chrono: merge to fix #8367.
Chrono: merge to fix #8435.
Chrono: merge [84411] to fix #8604.
Chrono: fix #8690.
Chrono: fix #8691,#8696 and update history.
Chrono: merge remove BOOST_TYPEOF_SILENT.