cleanup of instrumentation support, instrumentation-based timing fixed, misc refactorings

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

com.oracle.truffle.r.native/library/fastr/src/NAMESPACE

com.oracle.truffle.r.native/library/fastr/src/R/fastr.R

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

...truffle/r/nodes/builtin/base/HiddenInternalFunctions.java

...in/src/com/oracle/truffle/r/nodes/builtin/base/Parse.java

...cle/truffle/r/nodes/builtin/fastr/FastRFunctionEntry.java

...es/src/com/oracle/truffle/r/nodes/RSyntaxNodeVisitor.java

...cle/truffle/r/nodes/access/ReadVariadicComponentNode.java

.../src/com/oracle/truffle/r/nodes/control/SequenceNode.java

...acle/truffle/r/nodes/function/FunctionDefinitionNode.java

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

...acle/truffle/r/nodes/function/UUIDFunctionUIDFactory.java

...src/com/oracle/truffle/r/nodes/instrument/RASTProber.java

...com/oracle/truffle/r/nodes/instrument/REntryCounters.java

...rc/com/oracle/truffle/r/nodes/instrument/RInstrument.java

...src/com/oracle/truffle/r/nodes/instrument/RNodeTimer.java

...ptions/src/com/oracle/truffle/r/options/FastROptions.java

....runtime/src/com/oracle/truffle/r/runtime/RPerfStats.java

....runtime/src/com/oracle/truffle/r/runtime/RSerialize.java