ENH: simplify method names for reading argList options and arguments

- use succincter method names that more closely resemble dictionary
  and HashTable method names. This improves method name consistency
  between classes and also requires less typing effort:

    args.found(optName)        vs.  args.optionFound(optName)
    args.readIfPresent(..)     vs.  args.optionReadIfPresent(..)
    ...
    args.opt<scalar>(optName)  vs.  args.optionRead<scalar>(optName)
    args.read<scalar>(index)   vs.  args.argRead<scalar>(index)

- the older method names forms have been retained for code compatibility,
  but are now deprecated

applications/test/IOobjectList/Test-IOobjectList.C

@@ -49,9 +49,9 @@ int main(int argc, char *argv[])
     #include "createTime.H"
 
     wordReList matcher;
-    if (args.optionFound("re"))
+    if (args.found("re"))
     {
-        matcher = args.optionReadList<wordRe>("re");
+        matcher = args.readList<wordRe>("re");
         Info<<"limit names: " << matcher << nl;
 
     }