lib: speed up slow parts of the lib files; other small fixes

lib/misc.zsh

@@ -3,15 +3,15 @@ autoload -Uz is-at-least
 # *-magic is known buggy in some versions; disable if so
 if [[ $DISABLE_MAGIC_FUNCTIONS != true ]]; then
   for d in $fpath; do
-  	if [[ -e "$d/url-quote-magic" ]]; then
-  		if is-at-least 5.1; then
-  			autoload -Uz bracketed-paste-magic
-  			zle -N bracketed-paste bracketed-paste-magic
-  		fi
-  		autoload -Uz url-quote-magic
-  		zle -N self-insert url-quote-magic
-      break
-  	fi
+    if [[ -e "$d/url-quote-magic" ]]; then
+      if is-at-least 5.1; then
+        autoload -Uz bracketed-paste-magic
+        zle -N bracketed-paste bracketed-paste-magic
+      fi
+      autoload -Uz url-quote-magic
+      zle -N self-insert url-quote-magic
+    break
+    fi
   done
 fi
 
@@ -25,7 +25,7 @@ env_default 'LESS' '-R'
 alias _='sudo '
 
 ## more intelligent acking for ubuntu users
-if which ack-grep &> /dev/null; then
+if (( $+commands[ack-grep] )); then
   alias afind='ack-grep -il'
 else
   alias afind='ack -il'