Back-propagated fixes and changes from 5.15 release:
- SSH private key tools (PuTTYgen and Pageant) upgraded to PuTTY 0.71.
- Bug fix: Back-propagated SSH security fixes from PuTTY 0.71. 1729 vuln-rng-reuse vuln-rsa-kex-integer-overflow
- Bug fix: Reloading file in internal editor can cause unwanted upload of partially reloaded file. 1728