Fix bug in collection of functions

* rework __combined type inference
* add missing callable trait for variant functions
* fixes a few bug in typing and aliasing handling when handling
  collections of function
* validate the whole stuff

This commit closes #71
Extend normalize_tuple to visit dict comprehension
More string  conversion

* string -> char
* string -> double
Make std::tuple hashable

So that it can be used as a key for a dictionary.
Rework type inference combination

Relies on __combined rather than operator+. This is important to handle
tuples correctly, because

tuple<int,int> + tuple<int, int> == tuple<int,int, int, int>

while

__combined<tuple<int,int>, tuple<int, int>>::type == tuple<int, int>
Handle Y' rosetta code series

A very beautiful one, that once again raised a lot of errors...
Fix documentation typos
Merge pull request #73 from franckCJ/master

My comments on the documentation
Auto conversion from tuple to list when possible

The basic idea is to *always* rely on core::make_tuple to create tuple
and on decltype(core::make_tuple(...)) to refer to the type of a tuple.

The one can overload core::make_tuple to return a ltuple instead of a
tuple when all parameters have the same type. A ltuple is just a list
with another type. So it is iterable etc and behaves fine with pythonic.
And the extra type information makes it possible to convert it to a
tuple when going back to the Python world .

This commit closes #70.
Merge branch 'master' of github.com:serge-sans-paille/pythran
Fixing failfast for single threaded benchmarking
Add test coverage analyse

Based on pytest_coverage.
Pythran currently has a pretty decent 90% coverage rate!
Fix a few compilation warnings
Make all tests use -Wall

The goal is to detect warnings in pythonic, *but*
this is not perfect as it also detects warnings in the generated code,
and test cases are full of warnings, although this commit fixes quite a
lot of them.

This only affects test cases based on TestEnv.
Harmonize integer template parameter types

Sometimes int was used, sometimes long, sometimes unsigned long.
Now size_t is used *everywhere*
Initialize ifilter internal structure properly

The filter operator was not copied but default constructed. It was not
an issue until someone used a bounded function. Bounded function hold an
internal state that *must* be propagated.

This fixes #76.
Add python version used inside the README
Add support for operator module
Merge pull request #75 from xmar/operator_rebased2

Add support for operator module
Constant value in a module may not be a scalar