Major refactoring to lower memory consumption.

Package has been split into multiple structure loaded on demand: files, extra, depends.

They're saved and loaded completely separately.

debian/package_deps.go

@@ -0,0 +1,30 @@
+package debian
+
+import (
+	"strings"
+)
+
+// PackageDependencies are various parsed dependencies
+type PackageDependencies struct {
+	Depends           []string
+	BuildDepends      []string
+	BuildDependsInDep []string
+	PreDepends        []string
+	Suggests          []string
+	Recommends        []string
+}
+
+func parseDependencies(input Stanza, key string) []string {
+	value, ok := input[key]
+	if !ok {
+		return nil
+	}
+
+	delete(input, key)
+
+	result := strings.Split(value, ",")
+	for i := range result {
+		result[i] = strings.TrimSpace(result[i])
+	}
+	return result
+}