Merge pull request #227 in G/fastr from ~LUKAS.STADLER_ORACLE.COM/fastr:bugfix/truffle_update to master

* commit 'f781bcab':
  update Truffle dependency

* commit 'e4e16c37':
  The elementAt filter added to Predef

* commit '905606db':
  adopt arg cast pipelines
  copyright fix
  refactor .fastr.context api to remove explicit context creation; fix exit handling for such contexts, so that, e.g, q() works as expected

* commit '5f3b4035':
  fix static bug in RErrorHandling

* commit 'd1a026a0':
  fix several tests with syntaxtic errors, small fix to SetS4Object

Merge pull request #220 in G/fastr from ~LUKAS.STADLER_ORACLE.COM/fastr:bugfix/fastr_errors to master

* commit '4b4b6645':
  keep fastr_errors.log in ci

Merge pull request #216 in G/fastr from ~LUKAS.STADLER_ORACLE.COM/fastr:bugfix/conditional_map_node to master

* commit '457b9cff':
  work on nchar
  additional helpers in CastBuilder.Predef, bugfix in ConditionalMapNode

refactor .fastr.context api to remove explicit context creation; fix exit handling for such contexts, so that, e.g, q() works as expected

Merge pull request #215 in G/fastr from ~LUKAS.STADLER_ORACLE.COM/fastr:bugfix/triage_withVisible to master

* commit '5ccbbd88':
  temporarily disable warning in withVisible

* commit 'c31810a4':
  A couple of SuppressWarning annotations added to CastBuilder. A pipeline in the "all" builtin fixed.
  The "all" builtin partly reimplemented using the cast pipelines.
  CastNode factories added to CastBuilder.Predef. Cast nodes can be chained by means of the chain method declared in Predef.
  A lambda can be passed as an error message argument. A fix-up of the "springboard" test snippets parsing in chimney-sweeping.
  The shouldBe(Class) warning step added to CastBuilder.Predef. Also, the handling of RNull and RMissing fixed in FindFirstNode and the default value mapper.
  Builtin colSums fixed using chimney-sweeping

* commit 'e41080f3':
  The shouldBe(Class) warning step added to CastBuilder.Predef. Also, the handling of RNull and RMissing fixed in FindFirstNode and the default value mapper.
  Builtin colSums fixed using chimney-sweeping

A couple of SuppressWarning annotations added to CastBuilder. A pipeline in the "all" builtin fixed.

CastNode factories added to CastBuilder.Predef. Cast nodes can be chained by means of the chain method declared in Predef.

A lambda can be passed as an error message argument. A fix-up of the "springboard" test snippets parsing in chimney-sweeping.

The shouldBe(Class) warning step added to CastBuilder.Predef. Also, the handling of RNull and RMissing fixed in FindFirstNode and the default value mapper.

* commit '485c2118':
  small fixes to rbdiag

Merge pull request #213 in G/fastr from ~LUKAS.STADLER_ORACLE.COM/fastr:feature/builtin_sprint to master

* commit '1fcec839':
  work on DatePOSIXFunctions
  work on Complex
  work on ColonNode

Merge pull request #210 in G/fastr from ~ADAM.WELC_ORACLE.COM/fastr:feature/builtins_sprint to master

* commit '64a4b514':
  Removed redundant portions of the cast pipeline.
  Regenerated tests.
  Finessed implementation of as.vector function.
  Finessed implementation of all.names function.
  Added fallback specialization to as.call builtin.

Merge pull request #205 in G/fastr from ~LUKAS.STADLER_ORACLE.COM/fastr:feature/function_names to master

* commit '980ef441':
  improve function name heuristics

The shouldBe(Class) warning step added to CastBuilder.Predef. Also, the handling of RNull and RMissing fixed in FindFirstNode and the default value mapper.