Model refresh is triggered when the main window is focused; fixes #249
Refactored browser code to normalise error-handling across all methods
Disabled hiding of page elements
Browser will login if recreated, fixes #257; made recursive call on browser recreation invoke runBrowserOperation, so it's queued up in the thread pool
Platform-specific utilities
chromedriver processes are killed on close; fixes #261
Temporarily disabled issue card context menu; fixes #258
Disabled browser resize on window resize; fixes #256