Verbatim copy of CMTKStatistics from nat.as

* test required slight modifications of course
rename to cmtk.statistics
remove exe argument and roxygenise
fix typo in help
Teach cmtk.statistics to pass ... to cmtk tool

* use cmtk.call internally to prepare the system call
Merge branch 'feature/cmtk.statistics'

* feature/cmtk.statistics:
  Teach cmtk.statistics to pass ... to cmtk tool
  fix typo in help
  remove exe argument and roxygenise
  rename to cmtk.statistics
  Verbatim copy of CMTKStatistics from nat.as
* part way to closing jefferislab/nat.flybrains#16
Bump version to 1.5.11
failing test for neuronlistfh update problem

* see #152
Fix bug in updating neuronlistfh objects

* closes #152
* problem was that isTRUE(md5sum(f1)==md5sum(f2)) is never true if f1 and f2
  point to different files, because isTRUE is FALSE if TRUE has a names attribute
Simple option to use plyr to give progress bars/parallelisation
import plyr

* was thinking of suggesting but then doc links don't work and I think that I might make
  this behaviour the default very soon.
fix doc link
Examples of using plyr/parallel
Warn if resampling a neuron with multiple subtrees

* closes #151
Update README.md
Update README.md
tests: don't leave pdf lying around

* this happens when running in non-interactive mode with rstudio's build/test
Give cmtk.statistics Verbose argument (default F)
teach read.neuron(s) to read neuronlists

* closes #153
Merge branch 'feature/plyr'

* feature/plyr:
  Examples of using plyr/parallel
  fix doc link
  import plyr
  Simple option to use plyr to give progress bars/parallelisation