Make JS external & fix inserted links for non-root installations

Hi,

After installing this module I noticed the JS code for inserting the links into the TinyMCE editor could use some work.

Attached is a patch with the following improvements / fixes:
1/ Add link click code in an external JS file. This is to prevent from having A/ the same JS code in multiple tpl.php files and B/ allowing for easier maintenance if the JS code should change in the future (otherwise people overriding the .tpl.php files in their own theme would have to redo this on JS changes in future versions of this module).
2/ Remove the hardcoded call to a JS file at http://dscdev.valdev.org/sites/all/libraries/tinymce/jscripts/tiny_mce/t.... The addition of this JS file has been added in the tinymce_node_picker.module file
3/ Fixes a problem when adding a node link on a Drupal site where the site is not in the root (e.g. http://www.example.com/sub/). I added the basePath JS variable instead of hardcoding the path to "/node/XXX".

I hope you'll be able to review these changes, and if found OK, integrate them in the module.

Kind regards,
Sven Decabooter