Updated mediawiki/extensions
Project: mediawiki/extensions/ImageMap  527f092a26716cad6bc2e719e402e6490ccbee0e

Added or improved file documentation

* the general file documentation was added, expanded or fixed
* added check for the initialisation of the extension

Change-Id: I04a9a22f81ca3df72d7561faae32f8792dea65e8