print() now prints to Python streams, but sys.stdout still cannot be directly overriden.

Differences.md

@@ -25,7 +25,8 @@ Known issues are essentially bugs, misfeatures, and omissions considered such, a
 1. Some functions use ``assert()`` for argument checking, which will lead to crash if wrong argument types are passed/erroneous conditions are faced. This should be replaced with Python exception raising.
 1. It's not possible to override builtin functions in a general way. So far - no "builtins" module is implemented, so any overrides work within a current module only.
 1. There's no support for persistent bytecode, and running bytecode (vs running Python source). [#222](//github.com/micropython/micropython/issues/222)
-1. print() function doesn't use the Python stream infrastructure, it uses the underlying C printf() function directly. This means if you override sys.stdout, then print() won't be affected. [#209](//github.com/micropython/micropython/issues/209)
+1. <strike>print() function doesn't use the Python stream infrastructure, it uses the underlying C printf() function directly. This means if you override sys.stdout, then print() won't be affected. </strike>[#209](//github.com/micropython/micropython/issues/209)
+1. Currently, it's not possible to override sys.stdin, sys.stdout, sys.stderr (for efficiency, they are stored in read-only memory).
 1. Some more advanced usages of package/module importing is not yet fully implemented. [#298](//github.com/micropython/micropython/issues/298)
 1. <strike>Exception handling with generators is not fully implemented.</strike> (Some small details may need to be done yet.) [#243](//github.com/micropython/micropython/issues/243)
 1. str.format() may miss few advanced/obscure features (but otherwise almost completely implemented). [#407](//github.com/micropython/micropython/issues/407), [#574](//github.com/micropython/micropython/issues/574)