Refactor POST handling.

- Split into admin and user handlers, each admin page gets its own file now
- Enforce role access once for admin POST requests
- Automatically load POST logic for admin-based requests based on the referring page, otherwise automatically load all user request logic
- Add support for using custom POST handlers

post/admin/admin_settings_theme.php

@@ -0,0 +1,55 @@
+<?php
+
+if (isset($_POST['edit_theme_settings'])) {
+
+    validateCSRFToken($_POST['csrf_token']);
+
+    $theme = preg_replace("/[^0-9a-zA-Z-]/", "", sanitizeInput($_POST['theme']));
+
+    mysqli_query($mysqli,"UPDATE settings SET config_theme = '$theme' WHERE company_id = 1");
+
+    //Logging
+    mysqli_query($mysqli,"INSERT INTO logs SET log_type = 'Settings', log_action = 'Modify', log_description = '$session_name modified theme settings', log_ip = '$session_ip', log_user_agent = '$session_user_agent', log_user_id = $session_user_id");
+
+    $_SESSION['alert_message'] = "Changed theme to <strong>$theme</strong>";
+
+    header("Location: " . $_SERVER["HTTP_REFERER"]);
+}
+
+if (isset($_POST['edit_favicon_settings'])) {
+
+    validateCSRFToken($_POST['csrf_token']);
+
+    // Check to see if a file is attached
+    if ($_FILES['file']['tmp_name'] != '') {
+        if ($new_file_name = checkFileUpload($_FILES['file'], array('ico'))) {
+            $file_tmp_path = $_FILES['file']['tmp_name'];
+
+            // Delete old file
+            if(file_exists("uploads/favicon.ico")) {
+                unlink("uploads/favicon.ico");
+            }
+
+            // directory in which the uploaded file will be moved
+            $upload_file_dir = "uploads/";
+            //Force File Name
+            $new_file_name = "favicon.ico";
+            $dest_path = $upload_file_dir . $new_file_name;
+
+            move_uploaded_file($file_tmp_path, $dest_path);
+
+            $_SESSION['alert_message'] = 'File successfully uploaded.';
+        }else{
+
+            $_SESSION['alert_message'] = 'There was an error moving the file to upload directory. Please make sure the upload directory is writable by web server.';
+        }
+    }
+
+    //Logging
+    mysqli_query($mysqli,"INSERT INTO logs SET log_type = 'Settings', log_action = 'Modify', log_description = '$session_name updated the favicon', log_ip = '$session_ip', log_user_agent = '$session_user_agent', log_user_id = $session_user_id");
+
+    $_SESSION['alert_message'] = "You updated the favicon";
+
+    header("Location: " . $_SERVER["HTTP_REFERER"]);
+
+}