Added mediaType, pageZoom, limitsNavigationsToAppBoundDomains iOS-specific webview options, Added handlesURLScheme iOS-specific webview method, Added ContentWorld class, minor bug fixes

Added addUserScript, addUserScripts, removeUserScript, removeUserScripts, removeAllUserScripts WebView methods, Added initialUserScripts WebView option, Added UserScript and UserScriptInjectionTime classes, updated README.md, fix some wrong iOS swift return value on method call handler, added InAppWebViewMethodHandler native class

updated ios Cookie Manager, Added IOSCookieManager class and CookieManager.instance().ios.getAllCookies iOS-specific method, updated README.md

fixed iOS getCookies MyCookieManager, Added limited cookies support on iOS below 11.0 using JavaScript

Added support for Dart null-safety feature, Updated integration tests, Fixed missing properties initialization when using InAppWebViewController.fromInAppBrowser, Removed debuggingEnabled WebView option and added AndroidInAppWebViewController.setWebContentsDebuggingEnabled static method

Fixed missing clearHistory webview method implementation on Android, Fixed iOS crash when using CookieManager getCookies for an URL and the host URL is null

updated android androidx.webkit:webkit:1.3.0, fixed default value for AndroidInAppBrowserOptions.hideTitleBar

Reverted calling handler.post on Android when a WebView is created, Fixed iOS extra bottom padding when opening the keyboard, fix #429

added disableDefaultErrorPage Android-specific webview option, updated onCreateWindow event implementation

Updated onCreateWindow, onJsAlert, onJsConfirm, and onJsPrompt webview events, added onCloseWindow, onTitleChanged, onWindowFocus, and onWindowBlur webview events, added androidOnRequestFocus, androidOnReceivedIcon, androidOnReceivedTouchIconUrl, androidOnJsBeforeUnload, and androidOnReceivedLoginRequest Android-specific webview events, fix #403

Update README.md, Update missing docs, Fix pub.dev Health suggestions and Analysis suggestions, v3.4.0+1

added getScrollX and getScrollY webview methods, added HttpOnly and SameSite set cookie options, added animated option to scrollTo and scrollBy webview methods, Added error and message to the ServerTrustChallenge class for iOS, added contentInsetAdjustmentBehavior webview iOS-specific option, added getCertificate android-specific webview method, added copy and copyWithValue methods for webview class options

added new webview methods, added supporZoom webview option on iOS, bug fixes, prepare new version 3.4.0

added clearHistory webview methods on Android, setContextMenu and clearFocus webview methods, added ContextMenuOptions class

Added 'toString()' method to various classes in order to have a better output instead of simply 'Instance of ...', updated getOptions() method

added onPageCommitVisible event, updated dart code for new events and methods, updated docs, fix #367