Tigon SQL changed interface setup

Changed interface setup and added query rewriting to comply with Tigon SQL compiler expectations

Now each defined schema has an associated interface named `"<schemaName>" + "s"` defined in file `<hostname>.ifq`

The Tigon SQL queries are re-written, such that each occurrence of `" " +  "<schemaName>" + " "` is replaced by `" [" + "<schemaName>" + "]." + "<schemaName>" + " "` to create the corresponding gsql file.