Fix and wrap set_tail_from_fit

The c++ version of the tail fit is wrapped to python. I also changed
slightly the code so that when replace_by_fit is true the data is
changed all the way to the end of the Matsubara axis not only on the
interval where the fit was done.
Added predefined hamiltonians to operators
API change for tail fitters

python fit_tail, replace_by_tail ==> fit_tail_depr, replace_by_tail_depr
c++ set_tail_from_fit ==> fit_tail
Two fixes in tight binding part
Allow indices in gf_struct/operator names to be strings.
Fix in tail-matrix multiplication

Set order_max to correspond to the mask
[cmake] Fix cmake python for Ubuntu 14.04

There is a bug in Ubuntu 14.04 : the interpreter
does not return the correct position of the libpython.
We add the correct path to the path hints, at the end (lowest priority).
In most machines, the first hint is the correct answer.
Fix for issue #134

There was a bug in the transpose of the indices. Added a test.
Fix issue #128

This is just cosmetics but should be fine.
[gfs] add << operator for gfs

kept <<= for backward compatibility
TODO: clean doc and examples, possibly add deprecation warning
Modify det_manip to access determinant x_values and y_values
include map and fold headers into array.hpp
Revert "include map and fold headers into array.hpp"

This is not the right place for include...

This reverts commit 63fd1b8b2d91261a4fad1f8762d54f1a7eef5330.
[arrays] More include by default
Clean old boost and old mc_tools code (v1)
doc : install
doc exceptions
Implement mpi lib (1). Array, generic, base, vector

- Implement the basic structure of the mpi lib
  and specialization for arrays, basic types, std::vector
- adapted the array class for the lazy mpi mechanism
- pass tests on arrays :
   - scatter, gather on array<long,2> array<complex,2>, etc...
   - broadcast
- several files for readibility
- the std::vector coded but not tested.
- generic mecanism implemented and tested (mpi_generic test)
- added several tests for the mpi lib.
- TODO : more tests, doc...
fix mpi/vector, added test
added first draft of MPI documentation