Excluded *.svg, *.pdf and extensionless files from low-res photos

in the special thesis submodule.
There is no need to convert pdf, svg to jpeg and shrink even in
thesis draft mode.

chertex.sh

@@ -150,6 +150,13 @@ if [ $# -eq 1 ]; then
          largephototype=${largephotobase#*.} # file extension only
          largephotoname=${largephotofilename%.*} # path without extension
          largephotobasename=${largephotobase%.*} # basename without extension
+         # some filetypes don't fare well when converted to jpeg, so we will only run the 
+         # forced conversion and shrinking unless the file extension is one of the following:
+         # "" (empty string, ie no file extension)
+         # SVG
+         # PDF
+         if [ ! "$largephototype" == "" ] || [ ! "$largephototype" == "svg" ] || [ ! "$largephototype" == "SVG" ] || [ ! "$largephototype" == "pdf" ] || [ ! "$largephototype" == "PDF" ]; then
+            # if the photo is not already jpeg, convert it to jpeg
             if [ ! "$largephototype" == "jpg" ] && [ ! "$largephototype" == "jpeg" ] && [ ! "$largephototype" == "JPG" ] && [ ! "$largephototype" == "JPEG" ]; then
                echo "<thesis> Converting $largephotobase to JPG format"
                mogrify -format jpg $largephotofilename
@@ -160,6 +167,7 @@ if [ $# -eq 1 ]; then
             # https://stackoverflow.com/questions/6917219/imagemagick-scale-jpeg-image-with-a-maximum-file-size
             echo "<thesis> Shrinking $largephotobasename.jpg"
             convert $largephotoname.jpg -define jpeg:extent=300kb $largephotoname.jpg
+         fi
       done
       # update the modification and access time on the photosastrun file
       touch "$photoslastrun"