Fixes for fetch-language-data.sh (#360)

* Fixes for fetch-language-data.sh

* Portable path function, instead of `readlink -f`, which doesn't
  work on mac.
* Remove extra '/' character from DEST. It is added again later.
* Change "wrote" to "written" — clearer meaning of what was done.

* Update language-data

* Update sjd autonym
* Move ms-arab a few lines (automatic change from CLDR)

Updating to
https://github.com/wikimedia/language-data/commit/b485f5a1343ba6348faca8e4f4994fefe6c195e6

.gitignore

@@ -6,5 +6,6 @@
 /node_modules
 /dist
 data/supplementalData.xml
+/scripts/vendor
 /vendor
 .eslintcache

scripts/fetch-language-data.sh

@@ -2,8 +2,9 @@
 
 set -o errexit -o nounset -o pipefail
 
-BASEDIR=$(dirname "$(dirname "$(readlink -f "$0")")")
-DEST="$BASEDIR/src/"
+scriptdir() { perl -MCwd -e 'print Cwd::abs_path shift;' "$1"; }
+BASEDIR=$(dirname "$(dirname "$(scriptdir "$0")")")
+DEST="$BASEDIR/src"
 CLONEDIR="$BASEDIR/vendor/language-data"
 UPSTREAM="https://github.com/wikimedia/language-data.git"
 
@@ -30,4 +31,4 @@ echo "Transforming language-data"
 
 "$BASEDIR"/node_modules/browserify/bin/cmd.js "$CLONEDIR"/data/language-data.json -t "$BASEDIR"/scripts/transform.js -o "$DEST"/jquery.uls.data.js
 
-echo "language-data wrote to $DEST/jquery.uls.data.js"
+echo "language-data written to $DEST/jquery.uls.data.js"