Add support for MinTLS and MaxTLS options (Issue #5119)

Add support for MinTLS and MaxTLS options (Issue #5119)

- cups/http-private.h: Move TLS/SSL version options to separate version
  constants, make _httpTLSSetOptions take min/max version numbers.
- cups/tls-*.c: Update _httpTLSSetOptions and _httpTLSStart to use new min/max
  version numbers.
- cups/tlscheck.c: Update _httpTLSSetOptions call.
- cups/usersys.c: Support new SSLOptions values, update _httpTLSSetOptions call.
- scheduler/conf.c: Support new SSLOptions values, update _httpTLSSetOptions
  calls.