Revert "Revert "Merge pull #793: Dev Docs: New Glossary & JS Search Box""

This reverts commit 961d6c988f.

_plugins/autocrossref.rb

@@ -33,12 +33,37 @@ require 'yaml'
     def render(context)
       output = super
 
-      ## Load terms from file
+      ## Load terms from file only if we haven't loaded them before
       site = context.registers[:site].config
-      if !site.has_key?("crossref")
-        site['crossref'] = YAML.load_file("_autocrossref.yaml")
+      if !site.has_key?("crossref_loaded")
+
+        ## Load refs from file and then downcase them all so we can
+        ## easily detect when we define xrefs more than once
+        mixed_case_refs = YAML.load_file("_autocrossref.yaml")
+        unvalidated_refs = Hash.new
+        mixed_case_refs.each { |key, value|
+          unvalidated_refs[key.to_s.downcase] = value.to_s.downcase
+        }
+
+        if site.has_key?("crossref")
+          ## We already have refs loaded, so merge
+          site['crossref'].merge!(unvalidated_refs) {
+            |key, old_value, new_value|
+
+            if old_value != new_value
+              abort("Error: autocrossref key '#{key}' wants to point to both '#{old_value}' and '#{new_value}'")
+            end
+
+            new_value
+          }
+        else
+          ## We don't have refs loaded yet, so copy
+          site['crossref'] = unvalidated_refs
+        end
+        site['crossref_loaded'] = true
       end
 
+
       ## Sort terms by reverse length, so longest matches get linked
       ## first (e.g. "block chain" before "block"). Otherwise short
       ## terms would get linked first and there'd be nothing for long
@@ -74,7 +99,7 @@ require 'yaml'
             (?!\w)  ## Don't match inside words
             (?!`)   ## Don't match strings ending with a tic, unless the xref itself ends with a tic
           /xmi) {|s|
-              if term[1] == "DO NOT AUTOCROSSREF"
+              if term[1] == "do not autocrossref"
                   s.gsub(/( |$)/, "<!--noref-->\\&")
               else
                   "[#{s}][#{term[1]}]{:.auto-link}"