no need to check dependencies in hook_init

There is absolutely no need for all this sort of code in the module's hook_init:

function linkimagefield_init() {
// If Content, FileField, or ImageField is not available, immediately disable Link Image Field.
$disable = FALSE;
$message = '';

if (!module_exists('content')) {
$disable = TRUE;
$message = t('The Content Creation Kit needs to be installed for it to work properly.');
}

The .info file's dependencies list guarantees that this module will not be enabled without the required modules.