add a common php image to base webapp, z-push and kdav on (#138)

* adapt webapp container for new php base image
* clean out webapp dockerfile
* complete switch of webapp to php-fpm
* update config in web container
* update readme
* remove logging config from docker-compose.yml
* add php container to tagging and publishing

php/start-helper.sh

@@ -0,0 +1,30 @@
+#!/bin/bash
+
+php_cfg_gen() {
+	local cfg_file="$1"
+	local cfg_setting="$2"
+	local cfg_value="$3"
+	if [ -e "$cfg_file" ]; then
+		echo "Setting $cfg_setting = $cfg_value in $cfg_file"
+		if ! grep -q "$cfg_setting" "$cfg_file"; then
+			echo "WARNING: Config option $cfg_setting not found in $cfg_file! You may have misspelled the confing setting."
+			echo "define('$cfg_setting', '$cfg_value');" >> "$cfg_file"
+			cat "$cfg_file"
+			return
+		fi
+		case $cfg_value in
+		true|TRUE|false|FALSE)
+			sed -ri "s#(\s*define).+${cfg_setting}.+#\tdefine(\x27${cfg_setting}\x27, ${cfg_value}\);#g" "$cfg_file"
+			;;
+		*)
+			sed -ri "s#(\s*define).+${cfg_setting}.+#\tdefine(\x27${cfg_setting}\x27, \x27${cfg_value}\x27\);#g" "$cfg_file"
+			;;
+		esac
+	else
+		echo "Error: Config file $cfg_file not found. Plugin not installed?"
+		local dir
+		dir=$(dirname "$cfg_file")
+		ls -la "$dir"
+		exit 1
+	fi
+}