Fix #2963

Changed all file permissions settings throught the framework
and the documentation.

Also added configuration settings for CI_Log and CI_Image_lib
diff --git a/application/config/config.php b/application/config/config.php
index b6b3c9f..e8d30b6 100644
--- a/application/config/config.php
+++ b/application/config/config.php
@@ -264,6 +264,18 @@
 
 /*
 |--------------------------------------------------------------------------
+| Log File Permissions
+|--------------------------------------------------------------------------
+|
+| The file system permissions to be applied on newly created log files.
+|
+| IMPORTANT: This MUST be an integer (no quotes) and you MUST use octal
+|            integer notation (i.e. 0700, 0644, etc.)
+*/
+$config['log_file_permissions'] = 0644;
+
+/*
+|--------------------------------------------------------------------------
 | Date Format for Logs
 |--------------------------------------------------------------------------
 |