Documentation and minor fixes to function calls

...nodes/src/com/oracle/truffle/r/nodes/RTruffleVisitor.java

...com/oracle/truffle/r/nodes/access/AccessArgumentNode.java

.../src/com/oracle/truffle/r/nodes/builtin/RBuiltinNode.java

...e/truffle/r/nodes/builtin/base/UseMethodDispatchNode.java

.../com/oracle/truffle/r/nodes/function/ArgumentMatcher.java

.../src/com/oracle/truffle/r/nodes/function/EnvProvider.java

.../com/oracle/truffle/r/nodes/function/FormalArguments.java

.../src/com/oracle/truffle/r/nodes/function/PromiseNode.java

...es/src/com/oracle/truffle/r/nodes/function/RCallNode.java

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