Bug 1348273 - Convert crash annotations into a machine-readable list of constants; r=ted.mielczarek,njn,dholbert,mak,cpearce,mcmanus,froydnj,Dexter,jrmuizel,jchen,jimm,bz,surkov

This introduces the machinery needed to generate crash annotations from a YAML
file. The relevant functions are updated to take a typed enum (in C++) and an
integer constant (in JavaScript). A JavaScript wrapper around the crash
reporter service is provided to hold the constants. The existing whitelists
and blacklists of annotations are also generated from the YAML file and the
existing duplicate code has been consolidated. Once written out to the .extra
file the annotations are converted in string form and are no different than
the existing ones.

All existing annotations have been included (and some obsolete ones removed)
and all call sites have been updated including tests.

docshell/base/nsDocShell.cpp

@@ -1702,8 +1702,8 @@ NS_IMETHODIMP
 nsDocShell::SetRemoteTabs(bool aUseRemoteTabs)
 {
   if (aUseRemoteTabs) {
-    CrashReporter::AnnotateCrashReport(NS_LITERAL_CSTRING("DOMIPCEnabled"),
-                                       NS_LITERAL_CSTRING("1"));
+    CrashReporter::AnnotateCrashReport(CrashReporter::Annotation::DOMIPCEnabled,
+                                       true);
   }
 
   mUseRemoteTabs = aUseRemoteTabs;