Merge remote-tracking branch 'bigbluebutton/master' into mobile-ui-updates

.../main/java/org/bigbluebutton/presentation/PngCreator.java

...ton/presentation/imp/PdfToSwfSlidesGenerationService.java

...ava/org/bigbluebutton/presentation/imp/PngCreatorImp.java

bigbluebutton-web/grails-app/conf/UrlMappings.groovy

bigbluebutton-web/grails-app/conf/bigbluebutton.properties

bigbluebutton-web/grails-app/conf/spring/doc-conversion.xml

...gbluebutton/web/controllers/PresentationController.groovy

...org/bigbluebutton/web/services/PresentationService.groovy

clients/flash/air-client/src/Default.css

clients/flash/air-client/src/css/hdpi.css

clients/flash/air-client/src/css/ldpi.css

clients/flash/air-client/src/css/mdpi.css

clients/flash/air-client/src/css/xhdpi.css

clients/flash/air-client/src/css/xxhdpi.css

clients/flash/air-client/src/css/xxxhdpi.css

...rg/bigbluebutton/air/chat/views/skins/SendButtonSkin.mxml

...lient/src/org/bigbluebutton/air/main/views/MenuButtons.as

...c/org/bigbluebutton/air/main/views/MenuButtonsMediator.as

...rg/bigbluebutton/air/main/views/skins/MenuButtonSkin.mxml

...nt/src/org/bigbluebutton/air/presentation/models/Slide.as