When the platform is installed in server mode, if the user edit the URL
in his browser's address bar, he can get writing permissions on the
corpus stored on the server.

This is to avoid dependence problems when compiling the dictionary with
citation links.

The three modes are:

  - Reader: browse the corpus in read-only mode

  - Annotator: add sentences to the corpus and modify existing analysis

  - Manager: manage the structure of the corpus tree, i.e. add
    subdirectories to the corpus tree where it is possible

Now, when the user is asked for confirmation of changes, he or she will
get back to the invoking corpus page at the position of the modified
sentence.

This argument just forwards the current arguments of the reader
interface to the CGI 'savecorpus'.

We have now 3 modules for the corpus manager:

  - Corpus: operations on corpus tree

  - Corpus_manager: generation of HTML page without CGI arguments
    processing

  - Corpus_manager_cgi: just parses the query string and calls
    Corpus_manager to generate the right page