Changed api.Variable to have a machine readable value

The new contents of api.Variable are documented in
proc/variables.go.

Implements #243

service/api/conversions.go

@@ -1,7 +1,9 @@
 package api
 
 import (
+	"debug/dwarf"
 	"debug/gosym"
+	"fmt"
 	"strconv"
 
 	"github.com/derekparker/delve/proc"
@@ -57,12 +59,43 @@ func ConvertThread(th *proc.Thread) *Thread {
 }
 
 // convertVar converts an internal variable to an API Variable.
-func ConvertVar(v *proc.Variable) Variable {
-	return Variable{
-		Name:  v.Name,
-		Value: v.Value,
-		Type:  v.Type,
+func ConvertVar(v *proc.Variable) *Variable {
+	r := Variable{
+		Addr: v.Addr,
+		Name: v.Name,
+		Kind: v.Kind,
+		Len:  v.Len,
+		Cap:  v.Cap,
 	}
+
+	if v.DwarfType != nil {
+		r.Type = v.DwarfType.String()
+	}
+
+	if v.RealType != nil {
+		r.RealType = v.RealType.String()
+	}
+
+	if v.Unreadable != nil {
+		r.Unreadable = v.Unreadable.Error()
+	}
+
+	switch typ := v.RealType.(type) {
+	case *dwarf.FloatType:
+		r.Value = strconv.FormatFloat(v.Value.(float64), 'f', -1, int(typ.Size()*8))
+	default:
+		if v.Value != nil {
+			r.Value = fmt.Sprintf("%v", v.Value)
+		}
+	}
+
+	r.Children = make([]Variable, len(v.Children))
+
+	for i := range v.Children {
+		r.Children[i] = *ConvertVar(&v.Children[i])
+	}
+
+	return &r
 }
 
 func ConvertFunction(fn *gosym.Func) *Function {