Stopwords

http://trac.xapian.org/ticket/269#no1
- Gathering the list of Arabic Stop-words
- Include the stop-word lists from Snowball Project

I guess you're trying to use `$'\t'` here?  That's a bash-ism, and will only work as you expect if SHELL gets set to bash, which certainly won't happen on systems without bash installed.  I think you've not managed to get it quite right for bash either - if I un-double the `$` and echo the result to see how it expands in bash, I get:

```
$ echo sed 's/[$'\t' ]*|.*//;/^[$'\t' ]*$/d'
sed s/[$t ]*|.*//;/^[$t ]*$/d
```

But what you want is simply a **literal** tab character in this Makefile.mk.  How to insert one depends on what editor you're using.  Maybe just hitting the `tab` key will do it, but often that's mapped to some sort of smart indent function.  For example, in vim it's `Ctrl+V` `tab` to insert a literal tab.