Highlight of search phrase in class name

#### Purpose

Highlight search phrase in class name. Proposed design:
![image](https://cloud.githubusercontent.com/assets/8158551/4815817/44073f56-5eda-11e4-8251-5c6e575563a3.png)

#### Modifications

Added new converter `SearchHighlightClassMarginConverter`. It was hard to converter of members because in this case class name can be broken on two lines. We need handle both lines.

#### Additional references

[MAGN-4915](http://adsk-oss.myjetbrains.com/youtrack/issue/MAGN-4915).

#### Reviewers

@aosyatnik, @Benglin, please, take a look.