Add nyagos.access()
Trim spaces
Suppress warnings
go fmt ./...
Merge pull request #26 from mattn/cool-prompt

lua_e "print(nyagos.access('c:\\users\\hayama\\.nyagosx',0) and 'true' or 'false')"
false 
-> OK
lua_e "print(nyagos.access('c:\\users\\hayama\\.nyagos',0) and 'true' or 'false')"
true
-> OK

I accept your pull request. Thank you for nice patches.