Phono3py

- Command option parser of the phonopy tools is replaced from `optparse` to
`argparse`.
- The filenames used with these options were the positional arguments
previously. Now they are the command-line arguments, i.e., filenames have to
be put just after the option name like
`-f vasprun.xml-001 vasprun.xml-002 ...`.
- The names of auxiliary tools (`kdeplot` and `kaccum`) are changed, for which
the prefix phono3py- is added to the old names to avoid accidental conflict
with other script names already existing under bin directory.
- {ref}`sigma_cutoff_option` option was created.

- {ref}`normal_umklapp_option` option was made.
- Many minor updates: fixing bugs, improving usabilities.
- Improve of {ref}`auxiliary_tools_kaccum` and {ref}`auxiliary_tools_kdeplot`.

- Abinit code interface is implemented and now under the testing.
- Reduction of memory usage in RTA thermal conductivity calculation. This is
especially effective for larger unit cell case. Currently combinations with
--full_pp, --write_gamma_detail, and --simga(smearing method) are not
supported for this. Performance tuning is under going. In some case,
computation can be slower than the previous versions.

- This version works coupled with phonopy-1.11.8 or later.
- CRYSTAL code interface is implemented by Antti J. Karttunen.

- This is a maintenance release. This version must be used with phonopy-1.11.6
or later.

- `gaccum` is merged to `kaccum`. `gaccum` is removed. See
{ref}`auxiliary_tools_kaccum`.
- `kdeplot` is added. See {ref}`auxiliary_tools_kdeplot`.