Add global --debug flag. Unless this is set, debug information is now suppressed.

diff --git a/cmd/msg.go b/cmd/msg.go
index 5f7e555..861db75 100644
--- a/cmd/msg.go
+++ b/cmd/msg.go

@@ -39,7 +39,7 @@
 
 // Debug logs debug information
 func Debug(msg string, args ...interface{}) {
-	if Quiet {
+	if Quiet || !IsDebugging {
 		return
 	}
 	fmt.Print("[DEBUG] ")

diff --git a/cmd/msg_windows.go b/cmd/msg_windows.go
index 604dba6..6774ebd 100644
--- a/cmd/msg_windows.go
+++ b/cmd/msg_windows.go

@@ -19,7 +19,7 @@
 
 // Debug logs debug information
 func Debug(msg string, args ...interface{}) {
-	if Quiet {
+	if Quiet || !IsDebugging {
 		return
 	}
 	fmt.Print("[DEBUG] ")

diff --git a/cmd/util.go b/cmd/util.go
index 9169f54..5527153 100644
--- a/cmd/util.go
+++ b/cmd/util.go

@@ -15,10 +15,12 @@
 
 // Quiet, when set to true, can suppress Info and Debug messages.
 var Quiet = false
+var IsDebugging = false
 
 // BeQuiet supresses Info and Debug messages.
 func BeQuiet(c cookoo.Context, p *cookoo.Params) (interface{}, cookoo.Interrupt) {
 	Quiet = p.Get("quiet", false).(bool)
+	IsDebugging = p.Get("debug", false).(bool)
 	return Quiet, nil
 }
 

diff --git a/cmd/yaml.go b/cmd/yaml.go
index c629e1e..f0fbbdf 100644
--- a/cmd/yaml.go
+++ b/cmd/yaml.go

@@ -432,7 +432,6 @@
 	UpdateAsVendored            bool
 	Flatten                     bool
 	Flattened                   bool
-	dirty                       bool
 }
 
 // DependencyFromYaml creates a dependency from a yaml.Node.

diff --git a/glide.go b/glide.go
index 88f62ee..130a951 100644
--- a/glide.go
+++ b/glide.go

@@ -90,6 +90,10 @@
 			Name:  "quiet, q",
 			Usage: "Quiet (no info or debug messages)",
 		},
+		cli.BoolFlag{
+			Name:  "debug",
+			Usage: "Print Debug messages (verbose)",
+		},
 	}
 	app.CommandNotFound = func(c *cli.Context, command string) {
 		cxt.Put("os.Args", os.Args)
@@ -389,6 +393,7 @@
 
 func setupHandler(c *cli.Context, route string, cxt cookoo.Context, router *cookoo.Router) {
 	cxt.Put("q", c.GlobalBool("quiet"))
+	cxt.Put("debug", c.GlobalBool("debug"))
 	cxt.Put("yaml", c.GlobalString("yaml"))
 	cxt.Put("cliArgs", c.Args())
 	if err := router.HandleRequest(route, cxt, false); err != nil {
@@ -402,6 +407,7 @@
 		// TODO: Add setup for debug in addition to quiet.
 		Does(cmd.BeQuiet, "quiet").
 		Using("quiet").From("cxt:q").
+		Using("debug").From("cxt:debug").
 		Does(cmd.VersionGuard, "v")
 
 	reg.Route("@ready", "Prepare for glide commands.").