Fixed tool flavor detection for 32-bits systems

Fixes #20
Fixes #25

Author: cmaglie

Diff for: arduino/cores/tools.go

@@ -163,17 +163,17 @@ func (f *Flavour) isCompatibleWith(osName, osArch string) bool {
 		return regexpArmLinux.MatchString(f.OS)
 	case "linux,amd64":
 		return regexpAmd64.MatchString(f.OS)
-	case "linux,i386":
+	case "linux,386":
 		return regexpi386.MatchString(f.OS)
-	case "windows,i386", "windows,amd64":
+	case "windows,386", "windows,amd64":
 		return regexpWindows.MatchString(f.OS)
 	case "darwin,amd64":
 		return regexpmac32Bit.MatchString(f.OS) || regexpMac64Bit.MatchString(f.OS)
-	case "darwin,i386":
+	case "darwin,386":
 		return regexpmac32Bit.MatchString(f.OS)
 	case "freebsd,arm":
 		return regexpArmBSD.MatchString(f.OS)
-	case "freebsd,i386", "freebsd,amd64":
+	case "freebsd,386", "freebsd,amd64":
 		genericFreeBSDexp := regexp.MustCompile(osArch + "%s-freebsd[0-9]*")
 		return genericFreeBSDexp.MatchString(f.OS)
 	}

Diff for: arduino/cores/tools_test.go

@@ -28,15 +28,15 @@ func TestFlavorCompatibility(t *testing.T) {
 		Os   string
 		Arch string
 	}
-	windowsi386 := &os{"windows", "i386"}
+	windowsi386 := &os{"windows", "386"}
 	windowsx8664 := &os{"windows", "amd64"}
-	linuxi386 := &os{"linux", "i386"}
+	linuxi386 := &os{"linux", "386"}
 	linuxamd64 := &os{"linux", "amd64"}
 	linuxarm := &os{"linux", "arm"}
 	linuxarmbe := &os{"linux", "armbe"}
-	darwini386 := &os{"darwin", "i386"}
+	darwini386 := &os{"darwin", "386"}
 	darwinamd646 := &os{"darwin", "amd64"}
-	freebsdi386 := &os{"freebsd", "i386"}
+	freebsdi386 := &os{"freebsd", "386"}
 	freebsdamd64 := &os{"freebsd", "amd64"}
 	oses := []*os{
 		windowsi386,