Fix Squid tips + optimize its install in 4-server-options

roles/4-server-options/tasks/main.yml

@@ -16,6 +16,7 @@
 - name: Install pylibs (IIAB's python libs)
   include_role:
     name: pylibs
+  #when: pylibs_installed is undefined
   #when: pylibs_install    # Flag might be created in future?
 
 - name: SSHD -- also run by roles/1-prep/tasks/main.yml as required by OpenVPN
@@ -34,10 +35,10 @@
   include_tasks: roles/network/tasks/dhcpd.yml
   when: dhcpd_install is defined and dhcpd_install
 
-# LESS MAINTAINED as of July 2019: https://github.com/iiab/iiab/issues/1879
+# LESS MAINTAINED
 - name: Install Squid
   include_tasks: roles/network/tasks/squid.yml
-  when: squid_install is defined and squid_install
+  when: squid_install and squid_installed is undefined
 
 
 - name: Install Bluetooth - only on Raspberry Pi
@@ -69,7 +70,7 @@
 - name: WWW_OPTIONS (WWW_BASE should have been installed earlier)
   include_role:
     name: www_options
-  #when: www_options_install    # Flag might be created in future?
+  #when: www_options_installed is undefined    # NO: as we encourage frequent settings changes here, e.g. php.ini and many others!
 
 
 - name: Recording STAGE 4 HAS COMPLETED ==================

roles/network/tasks/squid.yml

@@ -1,4 +1,4 @@
-- name: "Install package {{ proxy }} -- IIAB will later overwrite its /etc/squid/squid.conf"
+- name: Install package '{{ proxy }}' -- IIAB will later overwrite its /etc/squid/squid.conf
   package:
     name: "{{ proxy }}"    # squid (or 'squid3' on vars/debian-8.yml, vars/raspbian-8.yml)
       # - cadaver

roles/network/templates/squid/allow_url_regexs

@@ -1,5 +1,5 @@
 # SEE ALSO /etc/squid/squid.conf
-#          /etc/squid/allow_url_regexs
+#          /etc/squid/allow_dst_domains
 #          https://wiki.squid-cache.org/SquidFaq/SquidAcl
 # put regular expressions that match desired urls
 translator