implement .External, .External2, .External.graphics, .Call.graphics and .Fortran

.../com/oracle/truffle/r/nodes/builtin/base/BasePackage.java

...oracle/truffle/r/nodes/builtin/base/DynLoadFunctions.java

...com/oracle/truffle/r/nodes/builtin/base/foreign/DotC.java

...ruffle/r/nodes/builtin/base/foreign/ForeignFunctions.java

...om/oracle/truffle/r/runtime/ffi/jnr/CRFFI_JNR_Invoke.java

...com/oracle/truffle/r/runtime/ffi/jnr/CallRFFIWithJNI.java

...com/oracle/truffle/r/runtime/ffi/jnr/JNR_RFFIFactory.java

...untime/src/com/oracle/truffle/r/runtime/FastROptions.java

...time/src/com/oracle/truffle/r/runtime/data/RPairList.java

...r.runtime/src/com/oracle/truffle/r/runtime/ffi/CRFFI.java

...untime/src/com/oracle/truffle/r/runtime/ffi/CallRFFI.java

...e.r.runtime/src/com/oracle/truffle/r/runtime/ffi/DLL.java