Replace use of "ie:" with "eg:"

Closes #36
Closes #46

Author: tianon

README.md

@@ -9,7 +9,7 @@ The core of how `gosu` works is stolen directly from how Docker/libcontainer its
 ```console
 $ gosu
 Usage: ./gosu user-spec command [args]
-   ie: ./gosu tianon bash
+   eg: ./gosu tianon bash
        ./gosu nobody:root bash -c 'whoami && id'
        ./gosu 1000:1 id
 

main.go

@@ -26,7 +26,7 @@ func version() string {
 func usage() string {
 	t := template.Must(template.New("usage").Parse(`
 Usage: {{ .Self }} user-spec command [args]
-   ie: {{ .Self }} tianon bash
+   eg: {{ .Self }} tianon bash
        {{ .Self }} nobody:root bash -c 'whoami && id'
        {{ .Self }} 1000:1 id
 

test.sh

@@ -3,7 +3,7 @@ set -e
 
 usage() {
 	echo "usage: $1 gosu-binary"
-	echo "   ie: $1 ./gosu-amd64"
+	echo "   eg: $1 ./gosu-amd64"
 }
 
 gosu="$1"