Move example and test headers out of include/pv

The only headers installed there should be
those for the official API of the module.

exampleServer/src/exampleServerMain.cpp

@@ -20,11 +20,12 @@
 
 #include <pv/standardField.h>
 #include <pv/standardPVField.h>
-#include <pv/exampleServer.h>
 #include <pv/traceRecord.h>
 #include <pv/channelProviderLocal.h>
 #include <pv/serverContext.h>
 
+#include <exampleServer.h>
+
 using namespace std;
 using std::tr1::static_pointer_cast;
 using namespace epics::pvData;