Feature dynamic classnames

[bbrala]

Added option for defining classnames. The default classnames will change soon so there will be no conflicts anymore with bootstrap and such. To give people who fixed this in their own CSS a chance to easily change it back i added the options for the classnames.

(object) options.classNames
Specifies the base class names of the contextmenu elements. This can be used to change the class names of some classes that might conflict with frameworks like Bootstrap.

// Classname configuration to be able avoid conflicts in frameworks
classNames : {

    hover:          'hover',          // Item hover
    disabled:       'disabled',       // Item disabled
    visible:        'visible',        // Item visible
    notSelectable:  'not-selectable', // Item not selectable

    icon:           'icon',           // Base icon class
    iconEdit:       'icon-edit',
    iconCut:        'icon-cut',
    iconCopy:       'icon-copy',
    iconPaste:      'icon-paste',
    iconDelete:     'icon-delete',
    iconAdd:        'icon-add',
    iconQuit:       'icon-quit'

}