Pasted

.cfg
.config
.properties
.xml
.craft
.js
.schematic
.sql
.zip
.html
.css
.php
 .*.old (where *=any other extension on the whitelist)
.*_old
.*.disabled
.*_disabled
.*.example
.*_example
.*.sample
.*_sample
 files that have no extension tend to be text files, so they should probably be downloadable as well