fix path miss in windows/add a new api create function (#23)

* fix path was not always correct in windows

* add new api create function for if the port was different with api file.

* Update api.go

remove no need commit


This commit was moved from ipfs/go-ipfs-http-client@8c87deb

client/httpapi/api.go

@@ -7,12 +7,12 @@ import (
 	"net/http"
 	gohttp "net/http"
 	"os"
-	"path"
+	"path/filepath"
 	"strings"
 
 	iface "github.com/ipfs/interface-go-ipfs-core"
 	caopts "github.com/ipfs/interface-go-ipfs-core/options"
-	homedir "github.com/mitchellh/go-homedir"
+	"github.com/mitchellh/go-homedir"
 	ma "github.com/multiformats/go-multiaddr"
 	manet "github.com/multiformats/go-multiaddr-net"
 )
@@ -73,7 +73,7 @@ func ApiAddr(ipfspath string) (ma.Multiaddr, error) {
 		return nil, err
 	}
 
-	apiFile := path.Join(baseDir, DefaultApiFile)
+	apiFile := filepath.Join(baseDir, DefaultApiFile)
 
 	api, err := ioutil.ReadFile(apiFile)
 	if err != nil {