0.3.0

New Features:

• Created an in memory ZipUTF8Writer for tests;
• Added formulas;
• Added Autofilter;
• Created an Length class;
• First step for threading;
• Added an OdsDocument.getOrAddTable() method;

Bug fixes:

• Examples with footer and header were not working

Misc:

• Renamed OdsFile to OdsDocument;
• Improved Javadoc;
• Improved Footer and Header classes design