improve performance for booleanSearchEngine
improve performance to underscore value function.
uncomment tests
improve test to bug with AND OR expression
fix bug with expression for fields without pattern
make simple search only in title and url fields.
Merge branch 'origin/master'

Conflicts:
	js/services/booleanSearchEngine.js
	test/unit/services/booleanSearchEngine.test.js
fix merge
fix small issues
Merge pull request #82 from artemgrygor/master

Boolean operators within words #80