Package log is a modification of the log package included in the Go standard
library, adding support for leveled logging, colorized output and JSON formatting.
A predefined 'standard' logger which is accessible through helper functions
Error[f|ln], Info[f|ln], Debug[f|ln], and Trace[f|ln]. The standard logger writes
to standard error and prints the filename and linenumber of the call site
of each logged message. Every log message is output on a separate line: if the
message being printed does not end in a newline, the logger will add one.