CB-8467

Added support for hiding the web view container.  This maintains the browser
session without closing it.  The browser window can be repeatedly hidden and
shown.

** This has only been tested on android and ios **

amazon/android:
An additional `hide` action was added to `InAppBrowser#execute`.  It is
identical to `show`, except that it calls `dialog.hide()` instead.

blackberry10:
no changes

firefoxos:
Added a `hide` method that is identical to `show`, indicating it is not
supported.

ios:
Added a `hide` method that is identical to `show`, except that it uses
`dismissViewControllerAnimated`.  It checks the value of
`_previousStatusBarStyle`.  If it is `-1`, the method returns with no
action performed.  If it is not, it is set to `-1.`

ubuntu:
Added a `hide` method that sets `CordovaWrapper.global.inappbrowser.visible` to
`false`.

windows:
Added a `hide` method that sets `browserWrap.style.display` to `none`.

wp:
Added a `hide` method that is identical to `show`, except that it sets
`browser.Visibility` to `Visibility.Collapsed` and sets `AppBar.IsVisible` to
`false`.

src/ubuntu/inappbrowser.cpp

@@ -65,6 +65,10 @@ void Inappbrowser::show(int, int) {
     m_cordova->execQML("CordovaWrapper.global.inappbrowser.visible = true");
 }
 
+void Inappbrowser::hide(int, int) {
+    m_cordova->execQML("CordovaWrapper.global.inappbrowser.visible = false");
+}
+
 void Inappbrowser::close(int, int) {
     m_cordova->execQML("CordovaWrapper.global.inappbrowser.destroy()");
     this->callbackWithoutRemove(_eventCb, EXIT_EVENT);

src/ubuntu/inappbrowser.h

@@ -46,6 +46,7 @@ public:
 public slots:
     void open(int cb, int, const QString &url, const QString &windowName, const QString &windowFeatures);
     void show(int, int);
+    void hide(int, int);
     void close(int, int);
     void injectStyleFile(int cb, int, const QString&, bool);
     void injectStyleCode(int cb, int, const QString&, bool);