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/services/surfaceflinger/MonitoredProducer.cpp b/services/surfaceflinger/MonitoredProducer.cpp
index 37a044e..e4e7d42 100644
--- a/services/surfaceflinger/MonitoredProducer.cpp
+++ b/services/surfaceflinger/MonitoredProducer.cpp
@@ -61,7 +61,7 @@
 }
 
 status_t MonitoredProducer::dequeueBuffer(int* slot, sp<Fence>* fence,
-        bool async, uint32_t w, uint32_t h, uint32_t format, uint32_t usage) {
+        bool async, uint32_t w, uint32_t h, PixelFormat format, uint32_t usage) {
     return mProducer->dequeueBuffer(slot, fence, async, w, h, format, usage);
 }
 
@@ -106,7 +106,7 @@
 }
 
 void MonitoredProducer::allocateBuffers(bool async, uint32_t width,
-        uint32_t height, uint32_t format, uint32_t usage) {
+        uint32_t height, PixelFormat format, uint32_t usage) {
     mProducer->allocateBuffers(async, width, height, format, usage);
 }