version 1.3.1
- added no logger: not-logging logger that just presents the 
  interface (conivenience for testing, and for integration
  with 'dcmodify')

version 1.2.1
- Added JSS reference.

version 1.1.5
- Loggers now have access to the file name and line numbers of the
  expression of which the action is being logged.
- The output of loggers 'cellwise', 'simple' and 'expression_logger'
  no contain a 'srcref' column, that gives file name and line number
  of the expression being logged. (thanks to anonymous reviewer B for
  suggesting)
- Fixed typos in documentation (thanks to anonymous reviewer B).


version 1.1.4
- When the $add() method of a loggger is called by lumberjack it now passes
  a 'meta' argument containing an 'src' string that is taken from the 'srcref'
  object when parsing the R script.
- internal changes

version 1.1.3
- bugfix: prefix label for file output was ignored since 1.1.2

version 1.1.2
- the 'file' argument in 'cellwise$new' is now called 'tempfile' to better reflect
  it's purpose.
- cellwise logger now warns when it encounters a duplicate key (this will corrupt
  logging info).
- 'run_file' gains argument 'envir'.
- new function 'source_file', with behaviour close to 'source'.
- stop_log now has 'dump' argument (default: TRUE) and passes ellipsis to $dump() method.
- Internal change: loggers now store internal data privately
- Changed licence to EUPL 1.2

version 1.0.3
- fixed test that triggered a CRAN error because it wrote in the installed
  area (Thanks to Kurt Hornik).

version 1.0.2
- fixed error caught on CRAN/Debian (an example wrote locally)

version 1.0.1
- fixed error caught on CRAN/Debian (an example wrote locally)

version 1.0.0
- Start tracking changes in R objects, by adding a single line of code to
  an existing script.
- New function 'run_file', track changes in scripts without '%L>%'
- Support for multiple loggers; loggers can now support an (automatic) label
  which is used to distinguish output files when multiple datasets are tracked.
- Argument 'log' is replaced by 'logger' in start_log(), dump_log() et al.
- Completely new vignette. Removed dependence on knitr.
- Completely reviewed the reference manual.
- Switched to 'tinytest' testing framework.

version 0.3.0
- '%L>%' is now considered the default lumberjack operator. '%>>%' remains as alias.
- Added 'expression_logger': log custom expressions
- Logging now also works for functions that remove the logging attribute.
- The 'cellwise' logger is now compatible with 'tibble' objects (thanks to
  Blain Bateman). 
- Some documentation improvements.

version 0.2.0
- Added '%L>%' as synonym to avoid possible confusion with 'pipeR::`%>>%`'
- Argument 'stop' of 'dump_log' is now 'TRUE' by default (was 'FALSE')
- New logger named 'filedump' dumps data versions to csv.
- Function 'stop_log()' will now call '<logger>$stop()' if defined.
- Package now depends on R >= 3.4.0. Some tests failed on Windows/OSX + R3.3.3

version 0.1.0
- initial release
