Reenable unboxed values

- Change INT to a type that remembers whether it was boxed or not.
- We still need a way of specifying a plain unboxed int, so add a
"phony" UNBOXED_INT.  UNBOXED_INT is not usable as a variable type,
but can be used to specify argument and return types.  It's up to
the receiver (irgen or type analysis) to convert UNBOXED_INT to
a usable INT.  Right now that's only guarded with a number of
asserts (and not through, say, the C++ type system).

This will fail even with the current workaround

Add cpythons method cache

Fix a rare 'assert R11 is not used' crash

disable moderate opt and pyston passes and increase reopt threshold

Add module "readline" and update CPython test notes.

handle the situation which provide a directory to pyston

My sym entry llvm stackmap patch contains a bug where it will emit stackmap entries with the wrong offset into the large constants array.
The problem is that the code assumes that the symbolic stack map constants are emitted at the end of the constants array,
but doen't take into consideration that "normal" large constants can be added after symbolic entries.
Thereby making the assigned offsets point to the wrong constants.
To fix this issue I'm calculating the offset for symbolic entries now at the very end when we know that the number of constants can't change anymore.
A nicer fix would be to not emit the symbolic entries inside the large cosntants array but instead into a special one.
But I think this is overkill for now and would like to todo this when the stackmap v2 code landed inside llvm in order to not have to implement it twice.

Try to fix "enforce return conventions" perf regression

Misc perf improvements

Pending review: add __call__ attribute to builtin functions and methods

We can rewrite a callattr where the getattr was done via a getattro,
if we are in CXX mode.  This got lost in the "enforce return conventions"
PR and resulted in a 4% slowdown on pyxl bench.

I think it's because the initial allocation of it fails.  This only shows
up in the debug build of lxml_test, which doesn't get tested through CI.

Add rewrite support for calls which use keyword args

Test against an old 0.5-series version of sqlalchemy

Use callattr inside PyObject_CallMethod*

After much investigation, I think this is the best option for now.
We might need to patch sqlalchemy or switch to refcounting.

The issue is that there's a dangling cursor that's left open, and
under cpython it will get closed quickly.  But for us, it's left open,
which keeps the connection open.  This leaves the table its referencing
locked.  But only in old versions of sqlite!  Newer versions are smart
enough to know that 'select current_timestamp() from table' does not
need to lock the table, so even though that select statement is still
running, it doesn't end up locking the table.

PyPy has a different issue with the test, where it closes the cursor too
early (not sure why).

Use travis_wait to workaround the no output received error

Add more Rewritable template args to functions

           django_template3.py             2.7s (4)             2.7s (4)  -0.3%
                 pyxl_bench.py             2.3s (4)             2.2s (4)  -4.1%
     sqlalchemy_imperative2.py             2.7s (4)             2.6s (4)  -1.4%
                       geomean                 2.5s                 2.5s  -2.0%

This exposed some other issues for us.