COMP: rename dictionary::read<T> to dictionary::readEntry<T>

- avoids compiler ambiguity when virtual methods such as
  IOdictionary::read() exist.

- the method was introduced in 1806, and was thus not yet widely used

src/OpenFOAM/db/functionObjects/functionObject/functionObject.C

@@ -66,7 +66,7 @@ Foam::autoPtr<Foam::functionObject> Foam::functionObject::New
     const dictionary& dict
 )
 {
-    const word functionType(dict.lookup("type"));
+    const word functionType(dict.get<word>("type"));
 
     if (debug)
     {