[ci skip] Merge pull request #4986 from ka7/feature/spelling

Spelling fixes in comment blocks and docs
diff --git a/system/database/DB_driver.php b/system/database/DB_driver.php
index 19afdd4..e52eb5c 100644
--- a/system/database/DB_driver.php
+++ b/system/database/DB_driver.php
@@ -1173,7 +1173,7 @@
 	// --------------------------------------------------------------------
 
 	/**
-	 * Platform-dependant string escape
+	 * Platform-dependent string escape
 	 *
 	 * @param	string
 	 * @return	string