first support for design documents

for the moment, one can generate a design document with the DSL if one
respects the following limitation: CommonJS modules are not supported
yet (even if the `require` function is present).

No check is performed on required modules. The dsl code generator should
have a symbol table for libraries to check whether they can be required.
Moreover, restrictions in function uses are not checked either for the
moment
couchdb configuration management

configuration of the CouchDB instance can now be managed directly from
Sohva
update lift version to release
fix copy of design with filters