Prevent fatals upon plugin activation

[dd32]

This object cache is distributed on https://wordpress.org/plugins/memcached/ as a plugin, but can't actually be used as one. The installation instructions do suggest it requires extra configutaration, but since most plugins only have junk there, no-one looks at it.

Due to the number of end-users who attempt to install it (See the support threads), only to be met with a fatal error, we should disable the plugin activation aspect of the plugin and present a useful error message to the end-user, rather than simply showing a fatal error.

I'm not sure of the best method to achieve this, but if it's going to be on WordPress.org/plugins it would be great to remove that "limitation".

[drzraf]

mu-plugins seems a good fit for this plugin
Would also be nice not to throw a fatal error if memcache is not installed / uninstalled / disabled.

[lucas-oliver-trondsen]

Can't somebody add a simple popup message that the user gets after he clicks the 'Install Now' button of this plugin, with a text like:

"Hey buddy, this is not a regular WordPress plugin that gets installed once you click the 'Install Now' button. You have to copy the object-cache.php file from this plugin to the wp-content directory of your website and check that you have properly installed and configured a Memcached server."