CMS 3547
CMS-3393 Image Selector - Add support for keyboard usage

Updated Checkbox.setChecked() method, removed duplicates and optimized.
Added missing spacebar pressed event.
CMS-3395 Wizard - Tabulator does not take me from name and into wiz step
CMS-3543 Display Name input field size does not grow with text
CMS-3579 Image Selector - Show placeholder while loading image
CMS-3476 Replace ExtJS grid - Try letting ContentGridPanel2 use ContentSummaryViewer to display the name column

Replaced basic NamesAndIconView with ContentSummaryViewer element.
Major update of the display style:
Updated columns width, colors, text align.
Updated Grid code, so it will react on Responsive UI events.
Fixed several firefox bugs, considering grid.
CMS-3402 Use icon class instead of urls for ComboBoxes
Merged master
Merge pull request #767 from enonic/CMS-3402

CMS-3402 Use icon class instead of urls for ComboBoxes
CMS-3547 Create and introduce context in Node and Content-api

Fixed irritating error that skipped has-child resolving
Merge pull request #765 from enonic/CMS-3476

CMS-3476 Replace ExtJS grid - Try letting ContentGridPanel2 use ContentS...
Merge branch 'master' into CMS-3547
Merge pull request #761 from enonic/CMS-3393

CMS-3393 Image Selector - Add support for keyboard usage
Merge pull request #762 from enonic/CMS-3395

CMS-3395 Wizard - Tabulator does not take me from name and into wiz step
Merge pull request #763 from enonic/CMS-3543

CMS-3543 Display Name input field size does not grow with text
Merge pull request #764 from enonic/CMS-3579

CMS-3579 Image Selector - Show placeholder while loading image
CMS-3478 Replace ExtJS grid - Support for expanding/collapsing content with children

Added collapsing with dynamic load.
Fixed styles.
Merge branch 'master' of github.com:enonic/wem-ce
Merge pull request #769 from enonic/CMS-3478

CMS-3478 Replace ExtJS grid - Support for expanding/collapsing content w...
CMS-3478 Replace ExtJS grid - Support for expanding/collapsing content with children

Replaced jQuery with ElementHelper.