v0.9.0

[minor] Stacktrace(err error) string - returns a prettified stacktrace of the error
[minor] StacktraceCustomFormat(msgformat string, traceFormat string, err error) string - supports using custom format
[minor] RuntimeFrames(err error) - returns runtime.Frames of the error, based on combined (if nested) program counters of the error
[minor] ProgramCounters(err error) []uintptr - returns combined (if nested) program counters of the error
[minor] fmt.Formatter interface implementation
[minor] HTTP status code and message support
[minor] File & line number prefixed to errors
[minor] Helper methods for different error types
[minor] Helper methods with formatting support for all error types