Merge branch 'master' into pr/1901

CMakeLists.txt

bin/unittestschema/address.json

contrib/natvis/rapidjson.natvis

doc/features.md

doc/schema.md

example/schemavalidator/schemavalidator.cpp

include/rapidjson/allocators.h

include/rapidjson/document.h

include/rapidjson/error/en.h

include/rapidjson/error/error.h

include/rapidjson/internal/biginteger.h

include/rapidjson/internal/diyfp.h

include/rapidjson/internal/dtoa.h

include/rapidjson/pointer.h

include/rapidjson/rapidjson.h

include/rapidjson/schema.h

include/rapidjson/writer.h

test/unittest/cursorstreamwrappertest.cpp

test/unittest/encodedstreamtest.cpp

test/unittest/ostreamwrappertest.cpp