utils: Update copyright year.
utils: Add edit_file().
utils: Add sep arg to condensed_traceback().
utils: Add formatted_exception().
utils: Add lines_without_comments().
utils: Add path_dirs().
utils: Add number_width().
utils.import_code: Delay sys.modules tweak.

It's better to add the new module to sys.modules after exec has finished.
Previously, if exec had problems, sys.modules would be in an invalid state
since it was changed prior to attempting the exec.
utils: Add buffer_str() and buffer_diff().
utils: Update wrapped_paragraphs() to use TextWrapper().
utils: Update cterm_rows_and_cols() to use pu.terminal.
utils: Update copy_file() to use shutil.copyfile().
utils: Add IntegerRange().
utils: Update die() to use warn().