tests for page with two a4j:push components stabilized
RFPL-2721: Metamer/PageFragments: fix TestPanelMenuIcon

Since fixed Attributes.set() for HTML select TestPanelMenuIcon became failing due to start verifying image icons. Add corect WebElement to locate image icon and move CSS classes sufixes to constants.
RFPL-2724: PageFragments: add RichFacesToolbarGroupSeparator

ToolbarGroup add only group separator markup in compare to Toolbar. Due to this don't need page fragment for toolbarGroup, need it for separator instead, which is sibling to toolbar item.
RFPL-2724: Metamer: Rewrite toolbarGroup using webdriver
page-fragments: added fragment for inplace select, refactored inplace input
showcase-ftest: inplace input test fix
showcase-ftest: inplace select test rewritten to Selenium 2
metamer: inplace input: aligning tests due to refactoring of fragment
metamer: added some missing styleClasses to basic attributes
metamer: added helper methods for testing events
metamer: rich:inplaceSelect: added JS Api buttons to sample
metamer: rich:inplaceSelect: tests converted to Selenium 2, testng-selenium2.xml updated
[page-fragment]: DropDownMenu added

* AbstractPopupMenu introduced to be a base class for both DropDownMenu
  and ContextMenu
[metamer-ftest][showcase-ftest]: contextMenu tests fixed

* fixed to use new Page fragments api

* test onmouseout fixed
[metamer-ftest]: DropDownMenu tests converted to Graphene2
page-fragments: checkbox fragment completed
page-fragments: message + messages fragment enhanced
metamer: graphValidator: updated sample and bean
page-fragments: calendar: refactored waiting methods
metamer: graphValidator: tests conversion to selenium  2, testng-selenium2.xml updated