mv.go: Fix errors

version and help flags are not defined
ls.go: Fix errors & a few changes

* help and version are undefined
* Added an errorChecker function
* Modified the getPath function to use os.Getwd if no path is given.
Add the go-coreutils implementation of wc 

Almost all functionality is there. The only thing missing is --files0-from=F and I'm not quite sure of the difference between counting bytes and characters.
Add wc
coreutils.txt: fix spelling mistake
Update wc.go
Remove uneeded usage line in help_text
Remove double dashes on two options
wc.go: Instead of panicking, print an error
wc.go: Shuffle cases around
wc.go: Remove extra lines from shuffling
wc.go: Reshuffle
Merge pull request #15 from mmstick/patch-1

Add the go-coreutils implementation of wc