Add new wrapper generator

- with pytriqs.wrap_test as an example.
gf : add indices, name in C++
gf: add a few functions in C++
gf : new wrapper
Cleaning h5 interface
minor correction for linux

- vector on C++14 has explicit default (until C++14 apparently)
  it is a small difference between libc++ and gnu libstdC++
parameters & wrapper

- new parameter class :
  parameters are viewed as form, built in C++, and filled in C++/python.
  Each field of the form as a precise C++ type (erased using standard techniques).
  First tests ok, to be reread/checked.

  TODO : serialization is commented. Lead to long compilation time & large code
  due to boost::serialization. Use h5 when possible.

- wrapper :
  - separated the converters of the wrapped type in the TRIQS library
  - necessary for parameters (it used outside an .so) and potentially
    other codes, outside an .so module
wrapper. Correction

- clean the call to py_converter.
- add a & in the generic function py2c (to be specialized later).
wrapper.

Correction converter specialization
(avoid redeclaration).
Fix a bug in simple_read_write.hpp
Fix compilation of py_converter.

- py_converters in hpp files
- add guard to prevent inclusion in the wrapper (to avoid 2
  specialisation of the same py_converter).
h5 serialization

- add an h5 serialization using hdf5 >= 1.8.9
  and a file in memory.
- following doc.
Fix wrong commit 068c4a1

The fix in simple_read_write was wrong. This should be correct now.
Fix h5 serialization: no test for old hdf5

- if version is  < 1.8.9, the test is ignored.
Serialization boost/h5 and clean parameters

- parameters : clean, add back serialization. Clean whitespace

- serialization : depending on the version of the hdf5 lib,
  uses h5 or boost.

- TODO : test it on a machine with new hdf5.
parameters : small details

- an include missing on OS X
- change serialization in the general case where hdf5 can be used,
  (version of hdf5 high enough) to use only one buffer,
  not a buffer per field.
- put back the mpi_param example.
gf_block converter
array & gf transpose

- implement transposed_view for arrays.
- .transpose method for gf
- wrapped to python
- add call op. for GfImTime, using C++
- Added ChangeLog
- rm matrix_stack
- start cleaning old code
gf. wrap legendre.
forgot one file