Merge pull request #579 in G/fastr from ~STEPAN.SINDELAR_ORACLE.COM/fastr:feature/stats-cleanup to master

* commit '483c080f':
  Stats code cleanup

- 'final' where possible
- do not assign to parameters
- removed duplicated code in GammaFunctions (which had a bug in it)
- warnings: do not save more than maxWanings warnings

Merge pull request #578 in G/fastr from ~STEPAN.SINDELAR_ORACLE.COM/fastr:feature/more-stats11 to master

* commit '60656d7f':
  Stats: port hypergeometric distribution
  Stats: port non-central F (nf) distribution
  Implement nbeta distribution functions in stats
  Implement nchisq distribution functions

Merge pull request #577 in G/fastr from ~STEPAN.SINDELAR_ORACLE.COM/fastr:feature/mlerror-refactoring to master

* commit 'e51f4cf9':
  Limit the number of warnings put into environment
  Stats errors/warnings methods actually implemented and moved to RMathError

+ small fix in RErrorHandling: when max number of warnings is reached, do not
report the actual number, but the max (like GnuR does).

Merge pull request #543 in G/fastr from ~MICK.JORDAN_ORACLE.COM/fastr:feature/truffle-rffi to master

* commit 'c9b4f171':
  testrffi: add test for C string null termination
  Initial Truffle RFFI implementation

Merge pull request #575 in G/fastr from ~LUKAS.STADLER_ORACLE.COM/fastr:feature/update_truffle to master

* commit 'e89ba976':
  update Truffle dependency

Merge pull request #574 in G/fastr from ~STEPAN.SINDELAR_ORACLE.COM/fastr:feature/better-stat-tests to master

* commit 'e66b86e4':
  Refactor tests of random distribution functions

Provide parameter values for each distribution separately +
honor semantics of common parameters like probability in [0,1] etc.

Few minor fixes of bugs discovered along the way.

Plus 'pgamma' external implemented.

Merge pull request #559 in G/fastr from ~MILOSLAV.METELKA_ORACLE.COM/fastr:utf8ToInt_builtin to master

* commit '0e33da46':
  Improved casts and removed extra specialization in utf8ToInt() builtin..
  Additional eclipse formatting.
  Implemented utf8ToInt builtin.

* commit '770b252b':
  use Java XZ; implement xzfile, bzfile .Internals

Merge pull request #570 in G/fastr from ~STEPAN.SINDELAR_ORACLE.COM/fastr:feature/more-stats8 to master

* commit 'e1295d32':
  Stat externals: qbeta, qf, qchisq
  Stat externals: ppois, qpois

Merge pull request #571 in G/fastr from ~LUKAS.STADLER_ORACLE.COM/fastr:bugfix/attr_in_specials to master

* commit '08375d00':
  use attribute node in SpecialsUtils

Merge pull request #550 in G/fastr from ~LUKAS.STADLER_ORACLE.COM/fastr:feature/cache_calltarget to master

* commit '79a3e14b':
  cache CallTargets in PolyglotEngineRootNode

Merge pull request #530 in G/fastr from ~LUKAS.STADLER_ORACLE.COM/fastr:feature/local_condition_handling to master

* commit '3ff79c88':
  store handler and restart stacks in frame slots only on demand

+ necessary DPQ/RMath methods
+ move all XChisq to Chisq.java

Merge pull request #569 in G/fastr from ~LUKAS.STADLER_ORACLE.COM/fastr:bugfix/cast_list_node to master

* commit 'af437d36':
  fix ordering of transferToInterpreter and node insertion in CastListNode

Merge pull request #566 in G/fastr from ~STEPAN.SINDELAR_ORACLE.COM/fastr:feature/more-stats7 to master

* commit 'b07b1106':
  Stat externals: qt, pt, punif, dunif, qunif, pgeom

Merge pull request #567 in G/fastr from ~LUKAS.STADLER_ORACLE.COM/fastr:bugfix/visibility_boolean to master

* commit '2cda4baf':
  set visibility in FunctionExpressionNode
  check for boolean frame slots in “executeEndOfFunction” and produce proper error message

Merge pull request #565 in G/fastr from ~LUKAS.STADLER_ORACLE.COM/fastr:bugfix/convert_index_NaN to master

* commit '3aadff8d':
  prevent NaN to 0L conversion in subset/subscript specials