Fix #661, refactoring price and time directives

* Refactoring rbsPriceInputDirective directive
* Refactoring rbsTimeIntervalInput directives
* Fix misanderstood between shared scope with directives and $watch using (in fact use attrs.$observe instead)
* Remove description meta variable (SEO) from product because there used Markdown and it's bad!
* Refactor SeoManager test to be consistent with the product description meta removing