Reorganize packages, closes #79

- All packages go into either cmd or pkg directories
- Most packages renamed
- Server packages moved into pkg/server
- sanitize moved into webui, as that's the only place it's used
- filestore moved into pkg/storage/file
- Makefile updated, and PKG variable use fixed

pkg/webui/recent.go

@@ -0,0 +1,35 @@
+package webui
+
+import (
+	"github.com/jhillyerd/inbucket/pkg/server/web"
+)
+
+const (
+	// maximum mailboxes to remember
+	maxRemembered = 8
+	// session value key; referenced in templates, do not change
+	mailboxKey = "recentMailboxes"
+)
+
+// RememberMailbox manages the list of recently accessed mailboxes stored in the session
+func RememberMailbox(ctx *web.Context, mailbox string) {
+	recent := RecentMailboxes(ctx)
+	newRecent := make([]string, 1, maxRemembered)
+	newRecent[0] = mailbox
+
+	for _, recBox := range recent {
+		// Insert until newRecent is full, but don't repeat the new mailbox
+		if len(newRecent) < maxRemembered && mailbox != recBox {
+			newRecent = append(newRecent, recBox)
+		}
+	}
+
+	ctx.Session.Values[mailboxKey] = newRecent
+}
+
+// RecentMailboxes returns a slice of the most recently accessed mailboxes
+func RecentMailboxes(ctx *web.Context) []string {
+	val := ctx.Session.Values[mailboxKey]
+	recent, _ := val.([]string)
+	return recent
+}