catch prev. uncaught exception, coverity issue 1121925
fixes #871
remove disabled debug output
fix tests to resemble the fixed duration calculation
implements #386
fixes #881
fix floating point accuracy woes on certain hardware platforms
use z0 parameters on z0
Add fwd decl to slash compile time
implements #872
re-enable cucumber tests on travis CI
compile on travis with the maximum number of cores
reverting back to two cores on travis
Some mild refactoring of the BinaryHeap code. style only
preparing call of turn penalty function
remove c-style calls to fabs
fix test regression
distinguish between left and right, thx @emiltin
fixes off-by-one and testing issue discussed in 889
Fix assertion in debug version

When running tests on FreeBSD 10 on debug verion I got boost assertion errors in mutex.hpp:79 . 

It seems that mutex unlock is not needed (it is already unlocked and behavior is undefined).