Allow specific recordings to be "delete protected" from disk-check.sh

@mcguirepr89 I'm very happy with how this turned out! 😄

scripts/advanced.php

@@ -204,7 +204,7 @@ if (file_exists('./scripts/thisrun.txt')) {
       <input name="full_disk" type="radio" id="purge" value="purge" <?php if (strcmp($newconfig['FULL_DISK'], "purge") == 0) { echo "checked"; }?>>Purge</label>
       <label for="keep">
       <input name="full_disk" type="radio" id="keep" value="keep" <?php if (strcmp($newconfig['FULL_DISK'], "keep") == 0) { echo "checked"; }?>>Keep</label>
-      <p>When the disk becomes full, you can choose to 'purge' old files to make room for new ones or 'keep' your data and stop all services instead.</p>
+      <p>When the disk becomes full, you can choose to 'purge' old files to make room for new ones or 'keep' your data and stop all services instead.<br>Note: you can exclude specific files from 'purge' on the Recordings page.</p>
       <label for="rec_card">Audio Card: </label>
       <input name="rec_card" type="text" value="<?php print($newconfig['REC_CARD']);?>" required/><br>
       <p>Set Audio Card to 'default' to use PulseAudio (always recommended), or an ALSA recognized sound card device from the output of `aplay -L`.</p>