fastboot: use cutils socket functions.

Now that cutils has cross-platform socket functionality, we can
restructure fastboot to remove platform-dependent networking code.

This CL adds socket_set_receive_timeout() to libcutils and combines the
fastboot socket code into a single implementation. It also adds TCP
functionality to fastboot sockets, but nothing uses it yet except for
the unit tests. A future CL will add the TCP protocol which will use
this TCP socket implementation.

Bug: http://b/26558551

Change-Id: If613fb348f9332b31fa2c88d67fb1e839923768a
diff --git a/fastboot/.clang-format b/fastboot/.clang-format
index 6737535..bcb8d8a 100644
--- a/fastboot/.clang-format
+++ b/fastboot/.clang-format
@@ -1,11 +1,14 @@
 BasedOnStyle: Google
 AllowShortBlocksOnASingleLine: false
-AllowShortFunctionsOnASingleLine: false
+AllowShortFunctionsOnASingleLine: Inline
 
 ColumnLimit: 100
 CommentPragmas: NOLINT:.*
 DerivePointerAlignment: false
 IndentWidth: 4
+ContinuationIndentWidth: 8
+ConstructorInitializerIndentWidth: 8
+AccessModifierOffset: -2
 PointerAlignment: Left
 TabWidth: 4
 UseTab: Never