[GR-4799] Debugging tutorial and related bugfixes/improvements.

...fle.r.engine/src/com/oracle/truffle/r/engine/REngine.java

...racle/truffle/r/engine/interop/RArgsValuesAndNamesMR.java

...c/com/oracle/truffle/r/engine/interop/REnvironmentMR.java

...e/src/com/oracle/truffle/r/engine/interop/RPromiseMR.java

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

...om/oracle/truffle/r/nodes/builtin/fastr/FastRInterop.java

...me/src/com/oracle/truffle/r/runtime/context/RContext.java

...ntime/src/com/oracle/truffle/r/runtime/data/RPromise.java

...e/src/com/oracle/truffle/r/runtime/interop/R2Foreign.java

.../oracle/truffle/r/test/library/fastr/TestJavaInterop.java

...est/src/com/oracle/truffle/r/test/tck/FastRDebugTest.java

...mentation/tutorials/debugging/InteropDebugging/JS/main.js

documentation/tutorials/debugging/InteropDebugging/R/main.r

...entation/tutorials/debugging/InteropDebugging/manifest.mf

...nteropDebugging/src/com/oracle/truffle/r/JavaMessage.java

...gging/InteropDebugging/src/com/oracle/truffle/r/Main.java

documentation/tutorials/debugging/R/binSearch.r

documentation/tutorials/debugging/R/dummy.r

documentation/tutorials/debugging/R/dump.r

documentation/tutorials/debugging/tutorial.md