Set of improvements and fixes #1

This PR contains series of improvements and fixes for indentation and highlighting. Hope it won't be a problem merging this batch instead of groups of PRs.

Changes:

- Highlighting for attributes like `@objc`, `@IBAction` etc;
- Highlighting for `self` and `super` keyword;
- Small fix for string interpolation highlighting, it leaked outside of the interpolation expression if string contained brackets;
- Indentation for function declaration work with various attributes (previously worked only with `override`);
- Fixed indentation issues for types with annotations (i.e. `Dictionary<String, String>`);
- Improvement multi-line hash and array indentation, behaves same as in Xcode;
- Fixed indentation issues for multi-line function calls when arguments contained optional(`?`) or unwrap(`!`) literal;
- Fixed indentation issues of statements inside `enum` declaration.