add gettext support and autotoolize

[tagoh]

That still could be done by in setuptools or distutils but autotoolizing is easier to keep the relevant scripts up to dated and maintain. I'm still using setup.py for minimal installation for python related things.

Once this is applied, everything should be improved and easy to do:

• make a dist file with "make dist"
• update po files with "make -C po update-po" when any strings changed.

and no need to maintain .gitignore anymore because of the efforts of git.mk (see git.mk for more details).

[tagoh]

forgot to add a gettext support code. the last commit should be 0038ed6 but anyway.