Allow to specify fine grained notification (e.g. deleting a document, folder)

Have access rights depending on document status. This will allow to
restrict access when a document is in a workflow or has been rejected.

There are still global variable in class LetoDMS_Bootstrap_Style

update tblWorkflowTransitionUsers and tblWorkflowTransitionGroups when
user or group is delete.

extend search by expiration date, add utitility to search for expiring documents

Settings::searchConfigFilePath() and Settings::getConfigDir() use different
approaches to get the configuration directory.

Show expiration status of documents in document list

Add a Search Function to Related Documents. When attaching a related document their should be a search function to easily find the document you would like to relate.

Export/Import content as xml (even for subfolders)

Copy folders recursivly

Allow operations like  delete, move, approve, etc. on a list of documents

Upload of multiple documents without an applet

Do not show documents which are not reviewed or approved or rejected

installation script:
- user simply unpack the tar.gz in a server folder and access that folder
- on startup if there are installation problems php automatically run the configuration script
- the data folder creation can be automatic (user/password for server) or manual (yet ready folder)
- same for the db and the db user
- db creation (run of create table.sql) shoul control if db is yet filled and control for update to do
- the inc/inc.Setting.php is filled asking user entry
- the script can be used to test installation problem without affecting the current installation

The document state is currently not updated when a user is deleted from users list. 
For example user A is the only pending approver for a document, then the document is in draft state.
When A is deleted the document should pass automatically in release status.
This could be done with a new function controlling the existance of all the pending approver/reviewer
and eventually updating the status of the document. This function will be called by user-remove function.

Sometimes in the DB are written messages strings in plain language whose 
language depends on the current user and will never be translated.
This can be avoided using only coded messages

The mail language is translated using the current user language but should use 
the receiver language (not easy).

In my Documents->all documents there should be two lists: one (the current) with 
the user's document, and another with the user's updated document (that's because 
one user could have updated a document not owned by himself)