switch linux screenshare images and text to real values

bigbluebutton-client/locale/en_US/bbbResources.properties

@@ -322,12 +322,12 @@ bbb.screensharePublish.helpText.MacChrome1 = 1. Locate 'screenshare.jnlp'
 bbb.screensharePublish.helpText.MacChrome2 = 2. Select 'Show In Finder'
 bbb.screensharePublish.helpText.MacChrome3 = 3. Right-click and select 'Open'
 bbb.screensharePublish.helpText.MacChrome4 = 4. Select 'Open' (if prompted)
-bbb.screensharePublish.helpText.LinuxFirefox1 = Placeholder linuxFirefox1
-bbb.screensharePublish.helpText.LinuxFirefox2 = Placeholder linuxFirefox2
-bbb.screensharePublish.helpText.LinuxFirefox3 = Placeholder linuxFirefox3
-bbb.screensharePublish.helpText.LinuxChrome1 = Placeholder linuxChrome1
-bbb.screensharePublish.helpText.LinuxChrome2 = Placeholder linuxChrome2
-bbb.screensharePublish.helpText.LinuxChrome3 = Placeholder linuxChrome3
+bbb.screensharePublish.helpText.LinuxFirefox1 = 1. Click 'OK' to run
+bbb.screensharePublish.helpText.LinuxFirefox2 = 2. Accept the certificate
+bbb.screensharePublish.helpText.LinuxFirefox3 = 
+bbb.screensharePublish.helpText.LinuxChrome1 = 1. Locate 'screenshare.jnlp'
+bbb.screensharePublish.helpText.LinuxChrome2 = 2. Click to open
+bbb.screensharePublish.helpText.LinuxChrome3 = 3. Accept the certificate
 bbb.screensharePublish.shareTypeLabel.text = Share:
 bbb.screensharePublish.shareType.fullScreen = Full screen
 bbb.screensharePublish.shareType.region = Region

bigbluebutton-client/src/org/bigbluebutton/modules/screenshare/view/components/ScreensharePublishWindow.mxml

@@ -490,6 +490,7 @@ with BigBlueButton; if not, see <http://www.gnu.org/licenses/>.
               info += "Chrome";
             }
           } else if (os == "Linux") {
+            shareTypeBox.visible = true;
             info = "Linux";
             if (browser == "Firefox") {
               info += "Firefox";