Update of the search engine of the help website

[Sylvestre Ledru]

Hello,

Just a quick email to let you that we update the search engine used by
the Scilab online help:
http://help.scilab.org/

The previous system used was slow (4 hours to generate the search
index... against 4 minutes now) and buggy.

Now, several issues have been fixed:
* words with underscore, _, are now accepted as keyword [1].
* The search engine is now available for the Japanese version [2].
* Wildcards searches are now also possible [3].
* Better quality and presentation of the results.


We also implemented a trick for the lazy users (I am the first one)
like with the bugtracker which is:
http://bugzilla.scilab.org/8888
will redirect to the right URL.

For the Scilab documentation, 
http://help.scilab.org/function_name will redirect to the right page in
the documentation. For example:
http://help.scilab.org/comet3d
will redirect to 
http://help.scilab.org/docs/5.3.3/en_US/comet3d.html

For those who are interested in the technical details, we drop Zend
Lucene (subliminal message: *don't use it*) and started to use Xapian
[5].

Regards,
Sylvestre

[1] http://help.scilab.org/docs/5.3.3/en_US/search/add_demo

[2] http://help.scilab.org/docs/5.3.3/ja_JP/search/isdir

[3] http://help.scilab.org/docs/5.3.3/en_US/search/plot*

[4] http://help.scilab.org/docs/5.3.3/ja_JP/search/fminsearch

[5] http://xapian.org/