Version 2.3.1 (stable)

Notable change in v2.3:

• Now detecting overflow in append and insert_r and throwing length_error (was already handled in most places)

Changes (minor) in v2.3.1:

• Performance fix: std::basic_string using std::allocator was not treated as trivially relocatable (same for boost::circular_buffer)
• Slightly better optimized for debug builds, and slightly better code-gen in release mode in some cases