Check_MK Werk 7182: Improved GUI extension error handling

ID: 7182 Title: Improved GUI extension error handling Component: Multisite Level: 2 Class: New feature Version: 1.6.0i1 When extending the standard GUI functionality, using either a manually installed <tt>local/share/check_mk/web</tt> plugin or a Check_MK extension package (MKP), exceptions may occur while loading the plugin. In previous versions these exceptions caused the whole GUI to fail making it impossible to repair the problem using the GUI, for example via the extension package manager of the CEE/CME. The extension related loading errors are now all catched and logged to the <tt>var/log/web.log</tt> instead of making the whole application fail. In addition to this, an error message will be shown on the "Extension packages" WATO page. We've also added a new Analyze configuration check "Broken GUI extensions" which will report a CRIT state when broken GUI extensions are found.