Merge pull request #503 in G/fastr from...

Merge pull request #503 in G/fastr from ~STEPAN.SINDELAR_ORACLE.COM/fastr:feature/prob-distr3 to master

* commit 'ff858293':
  TestRandGenerationFunctions: Ignore.Whitespace is enough to match GnuR warnings output
  Fix typo in RPois + Wilcox catches OutOfMemoryError
  Regenerate expected tests output + few more rxxx tests
  RDeparse: 'correct' spacing around '/'
  Implement rwilcox
  Implement C_rnbinom_mu for rnbinom with parameter mu
  Implement C_rnchisq adding support for rchisq with 3 arguments
  Implement 'rweibull'
  Implement 'rlogis'
  Implement 'rf'
  Implement rgamma + unified tests for all rxxx functions
  RRNG: save some allocations when handling .Random.seed
  Simplify RandFunctionX_Y interfaces