FIX: removed/encapsulated sudo to improve convenience

- replaced pip sudo with --user option
- made easy_install pip with sudo optional by checking if the pip command exists
- added comments

tools/FetchMacOS/fetch.sh

@@ -1,7 +1,27 @@
 set +x;
 SCRIPTDIR="$(dirname "$0")";
 cd $SCRIPTDIR
-sudo easy_install pip
-sudo -H pip install -r requirements.txt
+
+echo -ne "\e[1mchecking of pip is installed... \e[0m"
+# only try to install pip if it does not exist
+if ! hash pip 2>/dev/null; then
+	echo ""
+	read -p "Do you want me to install pip as root? " yn
+	case $yn in
+		[Yy]* ) sudo easy_install pip;;
+		* ) echo -e "\e[1mplease install pip and try again\e[0m"; exit;;
+	esac
+else
+	echo -e "\e[1m[OK]\e[0m"
+fi
+
+echo -e "\e[1mchecking/installing dependencies... \e[0m"
+# pip should now exist, only install packages to user home
+pip install -r requirements.txt --user
+echo -e "\e[1mfechting macOS... \e[0m"
+
+# now that all requirements should be fulfilled, start downloading the image
 python fetch-macos.py -p 041-71284 -c DeveloperSeed
+
+echo -e "\e[1mdone\e[0m"
 exit;