Now
===

- String escapes doesn't work inside bytes;

- When we check spelling we don't need to check the whole strings only the
  content. For example we don't need to check 'u' for spelling in strings
  like this: u"Some text";

Later
=====

- Highligh errors where symbols follow by numbers like this: 0o123LaB

- Need more accurate way to handle indentation errors. For example
  mixing spaces and tabs may be used for pretty formatting;

- Need more checks for errors like: absent brackets, absent quotes,
  back slash at the end of strings;