Use diffferent queries for searching
* Add assert_text, assert_no_text, assert_title, assert_no_title
* Refactor query resolving
* Improve failure messages for have_text, have_title RSpec matchers (they will be the same as for added assert_* methods)
* Add Simple#inspect
Merge pull request #1246 from abotalov/queries

Use diffferent queries for searching + provide better failure messages