Update .gitignore files based on svn:ignore properties

For the top-level .gitignore, do this via the existing patch.

debian/.gitignore

@@ -1,5 +1,18 @@
 !/patches
 !*.patch
 !*.diff
+*.debhelper*
+*.local
 *.pyc
+*.substvars
+*-di
+/build/
+/config.defines.dump
+/control
+/control.md5sum
+/files
+/linux-*
 /po/
+/rules.gen
+/stamps/
+/xen-linux-system-*

debian/changelog

@@ -2,6 +2,10 @@ linux (4.2~rc5-1~exp1) UNRELEASED; urgency=medium
 
   * New upstream release candidate
 
+  [ Ben Hutchings ]
+  * Adjust for migration to git:
+    - Update .gitignore files
+
  -- Ben Hutchings <ben@decadent.org.uk>  Tue, 04 Aug 2015 01:47:47 +0100
 
 linux (4.1.3-1) unstable; urgency=medium

debian/patches/debian/gitignore.patch

@@ -3,9 +3,11 @@ Date: Thu, 17 Jan 2013 08:55:21 +0000
 Subject: Tweak gitignore for Debian pkg-kernel using git svn.
 Forwarded: not-needed
 
+[bwh: Tweak further for pure git]
+
 --- a/.gitignore
 +++ b/.gitignore
-@@ -49,22 +49,11 @@ Module.symvers
+@@ -50,22 +50,11 @@ Module.symvers
  /Module.markers
  
  #
@@ -28,3 +30,13 @@ Forwarded: not-needed
  # Generated include files
  #
  include/config
+@@ -106,3 +95,9 @@ all.config
+ 
+ # Kdevelop4
+ *.kdev4
++
++#
++# Debian packaging: ignore everything at the top level, since it isn't
++# included in our repository
++#
++/*