Fix various little bugs and loosen up various warnings

Change-Id: Iead48ac030290290c7c448b6f72a31380c2e8326
diff --git a/third_party/libevent/BUILD b/third_party/libevent/BUILD
index 7c3fc10..50f714a 100644
--- a/third_party/libevent/BUILD
+++ b/third_party/libevent/BUILD
@@ -48,5 +48,15 @@
   copts = [
     '-Ithird_party/libevent/compat',
     '-Ithird_party/libevent/include',
+
+    # TODO(Brian): Fix the places in the code it uses char* as an intermediate
+    # type while doing offsetof stuff.
+    '-Wno-cast-align',
+
+    '-Wno-unused-parameter',
+    '-Wno-format-nonliteral',
+    '-Wno-cast-qual',
+    '-Wno-incompatible-pointer-types-discards-qualifiers',
+    '-Wno-unused-function',
   ],
 )