dev: remove StatET project remnants
Some minor doc fixes in nat-package and neuron
typo in README.md
note about neurodebian install/travis
prefix nocran tests with a . to fix negative regex problem on windows

* The original regex:
  
  "^(?:(?!nocran).)+$"

  failed on the winbuilder service
* replace with a simpler approach
* test files must _not_ have a period following the obligatory "test-" prefix
  if they are to be run on CRAN.
give memDecompress a compression type argument

* and pass on ...
fix reading of gzipped nrrds on windows

* somewhat simplifying the read.nrrd code in the process
* strange thing is I had a note that the approach (using a gzcon to wrap an
  open connection) failed with earlier versions of R.
Merge branch 'fix/read.nrrd-gzip-windows'

* the first change turns out not to be required for this fix but is a small
  improvement that might be helpful in other circumstances.
* fix/read.nrrd-gzip-windows:
  fix reading of gzipped nrrds on windows
  give read.zlib a compression type argument