Williamfgc refactor examples basics (#10)

* Added examples for variables

* fix more example code

* make Open explicit in ADIOS1 toolkit. Fix handling open mode

* fix OpenModeToString() to serve adios 1 API's needs as well

* fix basic examples after code refactoring

* fix nompi build for basic examples

* fix nompi build

* fix one more example for nompi build

examples/hello/adios1Writer/helloADIOS1Writer_nompi.cpp

@@ -22,7 +22,7 @@ int main(int argc, char *argv[])
     try
     {
         /** ADIOS class factory of IO class objects, DebugON is recommended */
-        adios::ADIOS adios(MPI_COMM_WORLD, adios::DebugON);
+        adios::ADIOS adios(adios::DebugON);
 
         /*** IO class object: settings and factory of Settings: Variables,
          * Parameters, Transports, and Execution: Engines */