fix typos

comment out unused code SFC_Step.RefreshBoundingBox()

explicitly mark unused variables found by pylint with _ or dummy

pylint don't ignores unused variables with '_' in the name, even when
they are started with '_'. This bug is already fixed upstream, to fix
this in all versions of pylint custom dummy-variables-rgx is used
'_+$|(_[a-zA-Z0-9_]*[a-zA-Z0-9]+?$)|dummy'

remove unused variables found by pylint

update .PHONE target in Makefile for mki18n.py

make mki18n return 0 on success

update list with files for internatialization, app.fil

move README content to Makefile

It's not necessary to copy commands from README anymore. Just use
'make source_list', 'make template' or 'make locales'.

fix pylint warning '(global-variable-not-assigned) Using global for 'X' but no assignment is done'

fix pylint error '(function-redefined) method already defined'

fix pylint warning '(unreachable) Unreachable code'

fix pylint warning (bad-indentation) Bad indentation. Found X spaces, expected Y

fix pylint warning '(pointless-string-statement) String statement has no effect'

Python doesn't support docstring for variables directly. Where
appropriate Sphinx style for docstrings for variables is used
'#: some-docstring'

fix error __init__ method from base class is not called

fix more than one statement on a single line