time affected by a stack exhaustion denial of service attack

time provides date and time handling in Rust. From 0.3.6 to before 0.3.47, when user-provided input is provided to any type that parses with the RFC 2822 format, a denial of service attack via stack exhaustion is possible. The attack relies on formally deprecated and rarely-used features that are part of the RFC 2822 format used in a malicious manner. Ordinary, non-malicious input will never encounter this scenario. A limit to the depth of recursion was added in v0.3.47. From this version, an error will be returned rather than exhausting the stack.