Global code ovehaul - remove CAS and other, add 15 minute greet check

- Remove CAS, as it no longer works for us
- Remove other checks
- Implement 15 minute greet timeout check
- Fix chat logos
- Ditch thirdparty logger, use stdlib log facility wrapper for logging

internal/mylog/level.go

@@ -0,0 +1,59 @@
+package mylog
+
+// The level vocabulary: what a level is called, how a name in free-form config
+// text becomes a Level, and how the configured threshold is changed without
+// reopening the destination.
+
+import (
+	"fmt"
+	"strings"
+)
+
+// ParseLevel maps a level name to a Level. Parsing is case-insensitive and
+// tolerates surrounding whitespace, because the level comes from free-form user
+// text in the config file. An unknown name is an error: Init and SetLevel are
+// programming-level calls where a typo should be loud.
+func ParseLevel(s string) (Level, error) {
+	switch strings.ToUpper(strings.TrimSpace(s)) {
+	case "TRACE":
+		return levelTrace, nil
+	case "DEBUG":
+		return levelDebug, nil
+	case "INFO":
+		return levelInfo, nil
+	case "WARN":
+		return levelWarn, nil
+	case "ERROR":
+		return levelError, nil
+	case "FATAL":
+		return levelFatal, nil
+	default:
+		return levelInfo, fmt.Errorf("%w %q, want one of trace, debug, info, warn, error, fatal", errUnknownLevel, s)
+	}
+}
+
+// SetLevel changes the level without reopening the destination.
+func SetLevel(loglevel string) error {
+	lvl, err := ParseLevel(loglevel)
+	if err != nil {
+		return err
+	}
+
+	lock.Lock()
+	defer lock.Unlock()
+
+	current.level = lvl
+
+	return nil
+}
+
+// name returns the uppercase token for the level.
+func (l Level) name() string {
+	if n, ok := levelNames[l]; ok {
+		return n
+	}
+
+	return "UNKNOWN"
+}
+
+/* vim: set ft=go noet ai ts=4 sw=4 sts=4: */