correcting error message for theme

When there was a theme parse error, alot was producing incorrect exception:

in read_config raise ConfigError((err_msg % str(themestring)) + e.message)
TypeError: cannot concatenate 'str' and 'ParseError' objects
Merge pull request #573 from lzap/theme-parse-error

correcting error message for theme
adding ctags to gitignore
Merge pull request #574 from lzap/tags-gitignore

adding ctags to gitignore