Move dhcpcd off its own getline.

Also move other stuff provided by bionic (or unused) out of the way.

Bug: 14499627
Change-Id: I29e15c5a978d2fa86b63df891c2f2e83eba009fc
Merge "Move dhcpcd off its own getline."
Really disable IPv6 RA processing in dhcpcd.

IPv6 RA processing in dhcpcd causes crashes, so we disabled it in
dhcpcd.conf. Unfortunately devices sometimes don't have the
config file, because one is not required for dhcpcd to work. So
disable IPv6 RA processing in the code too.

Bug: 15268738
Bug: 15779617
Change-Id: If3f904dc8a9cda9bdbf2ce424c4a3ecbb4c88fee
Merge "Really disable IPv6 RA processing in dhcpcd."
Always include <sys/...>, not <linux/...>.

Change-Id: I1d1d569d704485dd48e70da1927de95263db4fb6
Merge "Always include <sys/...>, not <linux/...>."
Fix DoS vulnerability in DHO_OPTIONSOVERLOADED.

Bug: 16677003
Change-Id: I6ac3318c04fa99d964e15aa2f06a5794daf61c7e
Suppress warning on comparing array with null.

BUG: 17356808
Change-Id: Iecd7c9407e388530a098681fcedb8f18c2ba5b38
Merge "Suppress warning on comparing array with null."
Merge "Fix DoS vulnerability in DHO_OPTIONSOVERLOADED."
Move check of IFF_LOWER_UP after all includes.

The latest uapi kernel headers use an enum for values such as
IFF_LOWER_UP. This code defines IFF_LOWER_UP and causes the inclusion
of if.h later on to mess up the enum definition.

Move the IFF_LOWER_UP check after all of the includes.

Change-Id: I9d9ce63a63bb6fc82a2424776f5aa6700cc34239
Merge "Move check of IFF_LOWER_UP after all includes."