Change recipe-installation instructions

Per problems with `pip install -r` when installing scipy and others.

c.f. pypa/pip#25

README.md

@@ -8,7 +8,7 @@ These are based on personal preferences; all relevant caveats apply.
 
 ```sh
 mkvirtualenv [whatever_name_you_want]
-pip install -r [file]
+./install-recipe.sh recipes/[RECIPE].txt
 ```
 
 ## Current Recipes

install-recipe.sh

@@ -0,0 +1,14 @@
+#!/bin/bash
+# Get requirements file and any extra args for pip
+REQ_FILE=$1
+shift
+PIP_ARGS=$@
+
+# Loop through requirements file
+while read LINE; do
+    NONCOMMENT=$(echo -n $LINE | sed -e "s/\s*#.*$//")
+    if [ -z "$NONCOMMENT" ]; then continue; fi
+    pip install $NONCOMMENT $PIP_ARGS || break
+done < $REQ_FILE
+
+exit