Merge pull request #345 in G/fastr from ~STEPAN.SINDELAR_ORACLE.COM/fastr:feature/cast_pipelines6 to master

* commit '585e352e':
  Revert back use of ReuseNonSharedNode as it cannot handle RSequences yet.
  UpdateLength and UpdateSlot: converted to cast pipelines
  UpdateDim and UpdateClass: converted to cast pipelines

Merge pull request #343 in G/fastr from ~STEPAN.SINDELAR_ORACLE.COM/fastr:feature/cast_pipelines5 to master

* commit 'f5c9cf50':
  Fix a test of sample builtin + minor code style fix
  Ignore.ErrrorContext for some of the new tests
  UpdateAttr/UpdateAttributes: converted to cast pipelines
  TraceFunctions: converted to cast pipeline
  Sort builtins: converted to cast pipeline
  ShortRowNames: converted to castpipelines
  Setwd: converted to cast pipelines
  Sample: converted to cast pipelines

Merge pull request #312 in G/fastr from ~STEPAN.SINDELAR_ORACLE.COM/fastr:feature/deferred-refcouting to master

* commit 'ef9010a1':
  Fix stylecheck issue
  ListBuiltin and Quote: make share permanent only when cached.
  ListBuiltin and Quote: handle sharing properly
  Reference counting for list elements
  Various tests for lists reference counting
  WriteIndexedVectorNode: only increment ref count for shareable, do not copy
  Fix UpdateDimNames: use the result of getNonShared()
  only increase element's refcount during list updates if necessary (if element changes)
  tests for list element duplication

Merge pull request #344 in G/fastr from ~LUKAS.STADLER_ORACLE.COM/fastr:feature/update_truffle to master

* commit '710a1173':
  update to latest Truffle

* commit 'beee4721':
  Regenerated tests.
  Fixed copyright and checkstyle problems.
  Reintroduced temporarily commented out code.
  Fixed rbind/cbind generic dispatch for data frames.
  Fixes to changing the state of data being transferred to shared.
  Functions updating dimnames and names are generic.
  Set attributes using method that correctly handles vectors.
  Handle recursion for environments send through channels.
  Minor fix to updateform builtin.
  Minor fixes to the seq builtin.
  Optimized passing of attributes through channels for otherwise serialized data.
  Fixes to passing environments through channels.
  Fixes to passing promises through channels.
  Optimized transmission of promises through channels.
  Added one more missing stats function.

Merge pull request #340 in G/fastr from ~LUKAS.STADLER_ORACLE.COM/fastr:feature/full_precision_sum to master

* commit '8bfe469e':
  use native code to implement "sum" with proper precision

Plus: assertions in RSharingAttributeStorage and removed unnecessary code from WriteIndexedVectorNode.

Lists can hold elements that are not in a consistent state with respect to the sharing model.
However, such elements are put into consistent state once they are read from the list, their
state can be inferred from the state of the owning list.

This means that temporary elements can be freely put into lists without incrementing their ref-count.
Moreover, when a list is copied into another variable or passed as an argument to a function,
we only have to increment the ref-count of the list (no recursion needed).

When accessing an element of a list, one should use ExtractListElement node, which handles
the transition to consistent state. This must be used wherever the state matters: when returning
the value as a result of a builtin, putting it into another list, putting it as an attribute, etc.
On the other hand, when one only wants to peek at the value, but then forget the reference,
it is OK to get it directly using getDataAt and similar methods.

Merge pull request #334 in G/fastr from ~LUKAS.STADLER_ORACLE.COM/fastr:performance/visibility to master

* commit 'd13af296':
  remove all non-optimized visibility schemes
  pass visibility through RCaller object

Merge pull request #332 in G/fastr from ~MICK.JORDAN_ORACLE.COM/fastr:feature/apache-compress to master

* commit '52cdbbcb':
  backout internal RCompression changes
  implement bzip2 decompression internally

Merge pull request #336 in G/fastr from ~LUKAS.STADLER_ORACLE.COM/fastr:bugfix/transfer_to_interpreter_debug to master

* commit 'f4279129':
  transferToInterpreter in DebugHandling

Merge pull request #335 in G/fastr from ~LUKAS.STADLER_ORACLE.COM/fastr:performance/intrinsify_strings to master

* commit 'd252df6f':
  intern strings during deserialization