Basic functionality

This release includes core functionality like:

1. Importing from BibTeX files in ACL Digital Library, IEEE Xplore, Scopus and Web of Science dialects;
2. Exporting to BibTeX files in the same dialects of item 1;
3. Retrieving, modifying and persisting objects;
4. Tagging documents;
5. Adding and maintaining Attachments;
6. GUI Browser.