added redo task, run for every argument, make atomic builds
initial tests
addead Head function for StringSlice
renamed Each to Map for StringSlice
moved StringSlice to its own file
added Each method to StringSlice, like Map, but returns nothing
call Each on Args since there's no output
- refactored string slice handling in a more functional way
- moved string slice test on their own module
- added safe functions for extracting head of a list
- implemented default behaviour for targets with an extension
- added tests