Packaging cleanup

* Declare compliance with policy 4.5.1
* Bump debhelper compat level to 13
* Update debian/watch to version 4

debian/control

@@ -1,10 +1,10 @@
 Source: http-parser
 Maintainer: Christoph Biedl <debian.axhn@manchmal.in-ulm.de>
 Homepage: https://github.com/joyent/http-parser
-Standards-Version: 4.5.0
+Standards-Version: 4.5.1
 Vcs-Browser: https://git.in-ulm.de/cbiedl/http-parser
 Vcs-Git: https://git.in-ulm.de/cbiedl/http-parser.git
-Build-Depends: debhelper-compat (= 12),
+Build-Depends: debhelper-compat (= 13),
 Priority: optional
 Rules-Requires-Root: no
 Section: libs

debian/watch

@@ -1,3 +1,4 @@
-version=3
 
-https://github.com/joyent/http-parser/tags .*/v?(\d.*)\.(?:tgz|tbz2|tar\.(?:gz|bz2|xz))
+version=4
+https://github.com/joyent/@PACKAGE@/tags \
+    .*/v?(\d.*)@ARCHIVE_EXT@