v 0.5.1

• Fix a bug with Mammen weights introduced in version 0.5 -> switch back to sample() function. To guarantee reproducibilty with Mammen weights, either a seed needs to be specified in boottest() or a global seed needs to be set via set.seed().
• Delete some unnecessary computations from boot_algo2() -> speed improvements
• For B = 2^(#number of clusters), Rademacher weights should have been enumerated -
  instead, they were drawn randomly and enumeration only occured for B > 2^(#number of clusters). Now, enumeration occurs if B >= 2^(#number of clusters).