update README

 - update how to install this package
refactor SAD
First version SpatialSADMap
cleanup SpatialSADMap.lua
MulAnySize first version
Remove trailing whitespace in MulAnySize.lua
Merge branch 'MulAnySize'
First version SpatialSADMap
First commit of usefulFunctions feature branch

   Added *.swp vim temporary files to .gitignore
   Created <usefulFunctions.lua> which now contains only the <ls> function
   Required the library above into <init.lua>
   Updated documentation (<README.md>)
'Problems' with # sign in the documentation
Improved documentation for <ls> function
Bug fix and revert sys.execute to sys.ls

   <require> requires the additional <eex/> to point to functions within the
      eex package
   <sys.ls> deals also with nil argument, sys.execute('/usr/ls')
      avoids using colours by default, but is not necessary if sorting on Linux
      is not performed
Added test on not existing $DATASET environment varialbe
Moved functions to local eex namespace + corrected mispelled DATASETs
Update README.md

Added eex.datasetsPath documentation
Cleaning up the code

Changed comments adding the <eex.> prefix
Corrected $EEX_DATASETS spelling
Added an 
 to whatever <dataset> was missing it
Update README.md

Missing <$> in the documentation
Update README.md

Missing forward slash in the <eex.datasetPath> doc.
Update usefulFunctions.lua

Added forward slash </> at the path to which $EEX_DATASETS is pointing and in the WARNING message advice
Automatically add `/` to `$EEX_DATASETS` if missing