Recheck code that does deps parsing

[Vasyl Zuzyak]

Code that possibly contains bad things

• f6c5c066b13f4c769434b08ee37a57f4dcc16f03
• 6e065836c5b31a48b376655f2daaec957b92c954

In other words we need to handle code like this in single way

index = Math.abs(parseInt((index || '0'), 10));

[Vasyl Zuzyak]

1. 52402be task: save handling of negative index
2. 99324a1 task: replace repetitive code with method call
3. c84e7e1 task: fixed 1 typo and 1 codestyle issue

[Vasyl Zuzyak]

• 50c6f10 task: use parse functions to avoid bugs and repetitive code
• b762cef utils: add parse functions

[Vasyl Zuzyak]

done