added tests for isLiteral
added some tests for methods of Formula
added tests for ClauseLike, ImmutableClause, MutableClause, moved CardinalityConstraintTest to the right package
abstract TPTP-format, add a comment in ClauseLike
rename Formula.deMorgan to Formula.nnfHelper which it really is, rename constant for "(" ")" to PARENL/PARENR, added tests for PLFormul.eval
changed nnfHelper to deMorgan with 'real' deMorgan behavior
added Tests for DIMACSParser, deleted unused import, corrected some little mistakes in ImmutablePLClauseTest
refactoring qdimacs2Formula and qdimacs2FOLClauses, added links with definition of the corresponding file formats
abstract FOLParser symbols, added some comments about method behaviour to DIMACSReader and DIMACSTest
already tested in CardinalityConstraintTest
add libpicosat.so for linux 64 bit, the library will now be loaded but crashes during the execition of the native code (picosat_add)
Use picosat-951 instead of 959, running fine on my Ubuntu-64bit-VM
Update version of jna to 4.1.0 (just to be up to date)
Update JPicosat-Interface to the new interface used since picosat-953.
Updated picosat libraries for OSX and Linux accordingly. TODO: Updated
libraries for Windows.
Updated Win 32 Bit Picosat to version 959
Updated Win 64 Bit Picosat to version 959
Updated Travis configuration
Set correct travis branch link in README
fixing merge conflict