Refactor CPU load

Use a single function name for collecting loadavg. Reduces pollution
(issue #28).
Refactor _lp_load_color: less code but same features.

liquidprompt

@@ -153,27 +153,26 @@ esac
 
 
 # get current load
-
-_lp_load_Linux()
-{
-    local load
-    load=$(awk '{print $1}' /proc/loadavg)
-    echo -n "$load"
-}
-
-_lp_load_FreeBSD()
-{
-    local load
-    load=$(LANG=C sysctl -n vm.loadavg | awk '{print $2}')
-    echo -n "$load"
-}
-
-_lp_load_SunOS()
-{
-    local load
-    load=$(LANG=C uptime | awk '{print substr($10,0,length($10))}')
-    echo -n "$load"
-}
+case "$LP_OS" in
+    Linux)
+        _lp_cpu_load () {
+            local load eol
+            read load eol < /proc/loadavg
+            echo "$load"
+        }
+        ;;
+    FreeBSD)
+        _lp_cpu_load () {
+            local bol load eol
+            read bol load eol < $<( LANG=C sysctl -n vm.loadavg )
+            echo "$load"
+        }
+        ;;
+    SunOS)
+        _lp_cpu_load () {
+            LANG=C uptime | awk '{print substr($10,0,length($10))}'
+        }
+esac
 
 
 #################
@@ -787,14 +786,9 @@ _lp_load_color()
     # Then we have to choose the values at which the colours switch, with
     # anything past yellow being pretty important.
 
-    local loadval
     local load
-    loadval=$(_lp_load_$LP_OS)
-    load=$(echo $loadval | sed 's/\.//g;s/^0*//g' )
-    if [[ -z "$load" ]] ; then
-        load=0
-    fi
-    let "load=$load/$_lp_CPUNUM"
+    load="$(_lp_cpu_load | sed 's/\.//g;s/^0*//g' )"
+    let "load=${load:-0}/$_lp_CPUNUM"
 
     if [[ $load -ge $LP_LOAD_THRESHOLD ]]
     then