plugins: lose the eval(), switch to include_once

Note that require_once is bad as well here, because it throws another
uncatched error as opposed to a warning when a file has not been found.
Now it is better in recovery, although 99% of the time this is supposed
to deal with syntax errors during bad core/plugin updates or manual
user edits.

It's also useful to note that the errors/warnings still make their way
to the crash reporter so we can do something about them.

Suggested by: @fabianfrz

src/etc/inc/plugins.inc

@@ -71,11 +71,7 @@ function plugins_services()
     $services = array();
 
     foreach (plugins_scan() as $name => $path) {
-        try {
-            eval('require_once \'' . addslashes($path) . '\';');
-        } catch (ParseError $e) {
-            error_log($e);
-        }
+        try { include_once $path; } catch (ParseError $e) { error_log($e); }
         $func = sprintf('%s_services', $name);
         if (function_exists($func)) {
             $workers = $func();
@@ -93,11 +89,7 @@ function plugins_cron()
     $jobs = array();
 
     foreach (plugins_scan() as $name => $path) {
-        try {
-            eval('require_once \'' . addslashes($path) . '\';');
-        } catch (ParseError $e) {
-            error_log($e);
-        }
+        try { include_once $path; } catch (ParseError $e) { error_log($e); }
         $func = sprintf('%s_cron', $name);
         if (function_exists($func)) {
             $workers = $func();
@@ -115,11 +107,7 @@ function plugins_syslog()
     $syslogs = array();
 
     foreach (plugins_scan() as $name => $path) {
-        try {
-            eval('require_once \'' . addslashes($path) . '\';');
-        } catch (ParseError $e) {
-            error_log($e);
-        }
+        try { include_once $path; } catch (ParseError $e) { error_log($e); }
         $func = sprintf('%s_syslog', $name);
         if (function_exists($func)) {
             $workers = $func();
@@ -154,11 +142,7 @@ function plugins_interfaces()
 
     // register / update interfaces
     foreach (plugins_scan() as $name => $path) {
-        try {
-            eval('require_once \'' . addslashes($path) . '\';');
-        } catch (ParseError $e) {
-            error_log($e);
-        }
+        try { include_once $path; } catch (ParseError $e) { error_log($e); }
         $func = sprintf('%s_interfaces', $name);
         if (function_exists($func)) {
             foreach ($func() as $intf_ref => $intf_data) {
@@ -199,11 +183,7 @@ function plugins_interfaces()
 function plugins_firewall($fw)
 {
     foreach (plugins_scan() as $name => $path) {
-        try {
-            eval('require_once \'' . addslashes($path) . '\';');
-        } catch (ParseError $e) {
-            error_log($e);
-        }
+        try { include_once $path; } catch (ParseError $e) { error_log($e); }
         $func = sprintf('%s_firewall', $name);
         if (function_exists($func)) {
             $func($fw);
@@ -218,11 +198,7 @@ function plugins_configure($hook, $verbose = false, $args = array())
     array_unshift($args, $verbose);
 
     foreach (plugins_scan() as $name => $path) {
-        try {
-            eval('require_once \'' . addslashes($path) . '\';');
-        } catch (ParseError $e) {
-            error_log($e);
-        }
+        try { include_once $path; } catch (ParseError $e) { error_log($e); }
         $func = sprintf('%s_configure', $name);
         if (function_exists($func)) {
             $workers = $func();
@@ -253,11 +229,7 @@ function plugins_xmlrpc_sync()
 {
     $sync_settings = array();
     foreach (plugins_scan() as $name => $path) {
-        try {
-            eval('require_once \'' . addslashes($path) . '\';');
-        } catch (ParseError $e) {
-            error_log($e);
-        }
+        try { include_once $path; } catch (ParseError $e) { error_log($e); }
         $func = sprintf('%s_xmlrpc_sync', $name);
         if (function_exists($func)) {
             foreach ($func() as $helper) {