handle collation and timezones based on env variables

...acle/truffle/r/nodes/builtin/base/DatePOSIXFunctions.java

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

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

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

...tin/src/com/oracle/truffle/r/nodes/builtin/base/Rank.java

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

...le.r.runtime/src/com/oracle/truffle/r/runtime/RError.java

...e.r.runtime/src/com/oracle/truffle/r/runtime/RLocale.java

...om/oracle/truffle/r/runtime/context/ChildContextInfo.java

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

...com/oracle/truffle/r/test/builtins/TestBuiltin_order.java

.../src/com/oracle/truffle/r/test/generate/FastRSession.java

...m/oracle/truffle/r/test/generate/GnuROneShotRSession.java