README improvements

Author: Evan Shaw

README.md

@@ -419,10 +419,9 @@ Version 1.0 of the driver recommended adding `&charset=utf8` (alias for `SET NAM
 See http://dev.mysql.com/doc/refman/5.7/en/charset-unicode.html for more details on MySQL's Unicode support.
 
 ## Context Support
-Since go1.8, context is introduced to `database/sql` for better control on timeout and cancellation.
-New interfaces such as `driver.QueryerContext`, `driver.ExecerContext` are introduced. See more details on [context support to database/sql package](https://golang.org/doc/go1.8#database_sql, "sql").
-
-In Go-MySQL-Driver, we implemented these interfaces for structs `mysqlConn`, `mysqlStmt` and `mysqlTx`.
+Go 1.8 added some `database/sql` methods that accept a `context.Context` parameter for better control over timeout and cancellation.
+See more details on [context support to database/sql package](https://golang.org/doc/go1.8#database_sql, "sql").
+Go-MySQL-Driver supports context deadlines, but not cancellation.
 
 ## Testing / Development
 To run the driver tests you may need to adjust the configuration. See the [Testing Wiki-Page](https://github.com/go-sql-driver/mysql/wiki/Testing "Testing") for details.