Extract common functions into a separate file

This is the start of an effort to organize devstack's code
to better document the requirements for configuring the individual
components.

Change-Id: I3476b76b9d1f9ee63687fb9898a98729118cbd84
diff --git a/tools/build_uec.sh b/tools/build_uec.sh
index 04e1a45..ed5a017 100755
--- a/tools/build_uec.sh
+++ b/tools/build_uec.sh
@@ -8,7 +8,10 @@
 
 # Keep track of the current directory
 TOOLS_DIR=$(cd $(dirname "$0") && pwd)
-TOP_DIR=`cd $TOOLS_DIR/..; pwd`
+TOP_DIR=$(cd $TOOLS_DIR/..; pwd)
+
+# Import common functions
+. $TOP_DIR/functions
 
 cd $TOP_DIR
 
@@ -34,7 +37,7 @@
 
 # Install deps if needed
 DEPS="kvm libvirt-bin kpartx cloud-utils curl"
-apt-get install -y --force-yes $DEPS || true # allow this to fail gracefully for concurrent builds
+apt_get install -y --force-yes $DEPS || true # allow this to fail gracefully for concurrent builds
 
 # Where to store files and instances
 WORK_DIR=${WORK_DIR:-/opt/uecstack}