backports: add list_first_entry_or_null

This was added in the following upstream commit:
commit 6d7581e62f8be462440d7b22c6361f7c9fa4902b
Author: Jiri Pirko <jiri@resnulli.us>
Date:   Wed May 29 05:02:56 2013 +0000

    list: introduce list_first_entry_or_null

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
backports: add strtobool()

This was added in the following upstream commit:
commit d0f1fed29e6e73d9d17f4c91a5896a4ce3938d45
Author: Jonathan Cameron <jic23@cam.ac.uk>
Date:   Tue Apr 19 12:43:45 2011 +0100

    Add a strtobool function matching semantics of existing in kernel equivalents

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
backports: add missing header for struct in6_addr

fw-api-d3.h in the iwlwifi driver uses struct in6_addr and somehow it
does not get included on all kernel versions like 2.6.25. This patch
adds the missing include for linux/in6.h to fix the problem.

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
backports: refresh on next-20131025

1   2.6.25              [  OK  ]
2   2.6.26              [  OK  ]
3   2.6.27              [  OK  ]
4   2.6.28              [  OK  ]
5   2.6.29              [  OK  ]
6   2.6.30              [  OK  ]
7   2.6.31              [  OK  ]
8   2.6.32              [  OK  ]
9   2.6.33              [  OK  ]
10  2.6.34              [  OK  ]
11  2.6.35              [  OK  ]
12  2.6.36              [  OK  ]
13  2.6.37              [  OK  ]
14  2.6.38              [  OK  ]
15  2.6.39              [  OK  ]
16  3.0.98              [  OK  ]
17  3.1.10              [  OK  ]
18  3.10.14             [  OK  ]
19  3.11.3              [  OK  ]
20  3.12-rc3            [  OK  ]
21  3.2.51              [  OK  ]
22  3.3.8               [  OK  ]
23  3.4.64              [  OK  ]
24  3.5.7               [  OK  ]
25  3.6.11              [  OK  ]
26  3.7.10              [  OK  ]
27  3.8.13              [  OK  ]
28  3.9.11              [  OK  ]

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>