change the deprecated -W flag to -Wextra and add a few additional warning flags
change the deprecated -W flag to -Wextra and add a few additional warning flags

CarlosCD/growl,coltonfisher/coltonfisher-growl,doshinirav/doshinirav-myversion,coltonfisher/coltonfisher-growl,CarlosCD/growl,doshinirav/doshinirav-myversion,doshinirav/doshinirav-myversion,doshinirav/doshinirav-myversion,coltonfisher/coltonfisher-growl,doshinirav/doshinirav-myversion,doshinirav/doshinirav-myversion,coltonfisher/coltonfisher-growl,CarlosCD/growl,coltonfisher/coltonfisher-growl,coltonfisher/coltonfisher-growl,doshinirav/doshinirav-myversion,CarlosCD/growl,coltonfisher/coltonfisher-growl,CarlosCD/growl,CarlosCD/growl,CarlosCD/growl