Fix F with vim when there is no line number

Addresses issue sampson-chen#50 in the parent repo.

When there were no line numbers in results (e.g., sag -g), F would fail.
This switches from cutting based on space-delimited fields to simply
removing everything after the first non-alphanumeric character (I tried
to use \s instead of \W, but it didn't seem to work).

sack

@@ -154,7 +154,7 @@ create_shortcut_cmd_vim() {
     cat > $sack__shortcut_cmd_path <<SHORTCUT
 #!/bin/bash
 sack__vim_shortcut=\$(sed -n "\$1p" < $sack__shortcut_file)
-sack__line=\`echo \$sack__vim_shortcut | cut -d" " -f1\`
+sack__line=\`echo \$sack__vim_shortcut | sed 's/\W.*//'\`
 sack__file=\`echo \$sack__vim_shortcut | sed 's/'\$sack__line' //'\`
 if [ -z "\$EDITOR" ]; then
     sack__editor="$sack__default_editor"