libgui: Enable -Weverything and -Werror

Enables -Weverything and -Werror, with just a few exceptions for
warnings we can't (or shouldn't need to) work around.

This is a squashed commit based on an initial change with a couple of
fixes to avoid breaking certain targets. The source commits are:
  d723bd7669b4fc88dc282d8bf8ba5ecb2849d22f
  00d504c06ea034befe143e6b8cb34d004670ed02
  429ba89cd293633d2f882165066b422c96597df2

Change-Id: I034abec27bf4020d84af60d7acc1939c59986dd6
diff --git a/libs/gui/BufferQueueConsumer.cpp b/libs/gui/BufferQueueConsumer.cpp
index 36e3c06..a798b18 100644
--- a/libs/gui/BufferQueueConsumer.cpp
+++ b/libs/gui/BufferQueueConsumer.cpp
@@ -488,7 +488,7 @@
     mConsumerName = name;
 }
 
-status_t BufferQueueConsumer::setDefaultBufferFormat(uint32_t defaultFormat) {
+status_t BufferQueueConsumer::setDefaultBufferFormat(PixelFormat defaultFormat) {
     ATRACE_CALL();
     BQ_LOGV("setDefaultBufferFormat: %u", defaultFormat);
     Mutex::Autolock lock(mCore->mMutex);