+ * This file is the entry point for all API queries.
+ *
+ * It begins by checking whether the API is enabled on this wiki; if not,
+ * it informs the user that s/he should set $wgEnableAPI to true and exits.
+ * Otherwise, it constructs a new ApiMain using the parameter passed to it
+ * as an argument in the URL ('?action=') and with write-enabled set to the
+ * value of $wgEnableWriteAPI as specified in LocalSettings.php.
+ * It then invokes "execute()" on the ApiMain object instance, which
+ * produces output in the format sepecified in the URL.