Whats new in SAT4J 2.1?

Explanation support:
http://www.sat4j.org/maven21/org.sat4j.core/xref-test/org/sat4j/TestQuickExplain.html

Programmatic way to get Dimacs variable free id from the solver:
http://www.sat4j.org/maven21/org.sat4j.core/xref-test/org/sat4j/TestFreeId.html

Possibility to iterate over optimal solutions:
http://www.sat4j.org/maven21/org.sat4j.core/xref-test/org/sat4j/minisat/core/Bug275101.html

Search Listeners can now be hooked to an ISolver:
http://www.sat4j.org/maven21/org.sat4j.core/apidocs/org/sat4j/specs/package-summary.html

Search Listeners can display user defined dimacs to domain object mapping:
http://www.sat4j.org/maven21/org.sat4j.core/apidocs/org/sat4j/minisat/core/TextOutputListener.html#TextOutputListener(java.util.Map)
http://www.sat4j.org/maven21/org.sat4j.core/apidocs/org/sat4j/minisat/core/DotSearchListener.html#DotSearchListener(java.lang.String,%20java.util.Map)

Easy domain object constraints creation:
http://www.sat4j.org/maven21/org.sat4j.pb/xref-test/org/sat4j/pb/TestDependencyHelper.html

Improved MAXSAT and Weighted MAXSAT reader thanks to a custom EfficientScanner class:
http://www.sat4j.org/maven21/org.sat4j.core/xref/org/sat4j/reader/EfficientScanner.html

Allow BigInteger in weighted clauses:
http://www.sat4j.org/maven21/org.sat4j.maxsat/xref/org/sat4j/maxsat/WeightedMaxSatDecorator.html#176

Bug fixes:
[ #312655 ] ArrayIndexOutOfBoundsException
http://forge.ow2.org/tracker/index.php?func=detail&aid=312655&group_id=228&atid=350289