* development:
Bump yotta patch version
Merging iotssl-457-badtail with development branch
Moe top-level Readme to markdown
Changelog entry fro the previous commit
Add NULL checks to top-level SSL functions
Skip to trusted certs early in the chain
Add tests for verify callback
Improve mbedtls_ssl_write() documentation
Add mbedtls_ssl_get_max_frag_len()
Print "thread ID" in debug messages
Only use -Wshadow with GCC 4.8 or higher
Fix error reporting in pkey/pk_* programs
Fix more comments/outputs in verify programs
Fix hash buffer size in pkey programs
Change default RSA key size in rsa_genkey
Fix comments about filenames in some programs
Fix memory corruption in rsa sign/verify programs
Fix warning with MD/SHA ALT implementation
Fix handling of long PSK identities
Fix -Wshadow warnings
