Log Message:
libfilezilla: update to 0.31.0.

0.31.0 (2021-07-28)

+ Added simple JSON parser
+ Added basic JWS generator
- Made fz::file movable
- Fixed empty creation_flag for fz::file if other flags are also passed

0.30.0 (2021-07-09)

+ Added a flag to fz::file::creation_flags to create files with permissions only \ 
granting the current user and administrators access
+ Added mkdir_permissions flags to fz::mkdir

0.29.0 (2021-07-02)

+ Added fz::tls_layer::set_min_tls_ver and for testing purposes set_max_tls_ver
+ The TLS layer now also supports server-side session resumption with TLS <= \ 
1.2 clients not supporting session tickets
+ Added fz::rename_file
+ MSW: Added libfilezilla/glue/windows.hpp to set proper defines before \ 
including windows.h
+ Added fz::move_assign_through_move_constructor for classes that depend on \ 
normal destruction order even on move assignment
- Fixed memory leak in fz::tls_layer::set_alpn
- IPv6 listen sockets are now always created with IPV6_V6ONLY to unify behavior \ 
across platforms
- Fixes for issues found by --socketdebug
- Fixed warnings when bool arguments are passed to fz::sprintf
- Fixed warnings in fz::to_integral<bool>

0.28.0 (2021-05-03)

+ Added fz::hostname_lookup
+ Added fz::datetime::set_rfc3339
+ Added fz::load_certificates and fz::load_certificates_file
+ Added fz::base64_encode_append
- Moved some common functionality shared by multiple layers to socket_layer itself
- Fixed a crash with older versions of GnuTLS if the system trust store cannot \ 
be loaded

0.27.1 (2021-03-15)

- Fixed a socket event sequencing invariant violation in tls_layer
- Fixed query_string constructor leaving object in undefined state if set fails
- Fixed arguments passed from the templated equal_constime helper