Change raw_write usage to writen_any.

[pboothe]

raw_write is unsafe in the presence of websockets, and it relies too heavily on write() and SSL_write having the same error semantics. Use writen_any instead.

[stephen-soltesz]

write_raw & write_ssl - returns

• -1 recoverable
• 0 unrecoverable

• 0 success

writen_any - returns

• n/a -- exit due to signal handler (e.g. sigpipe)
• exit if return from write_raw or write_ssl is zero.
• 0 if original "amount" is zero.

• 0 success.

send_msg_any - uses return value from writen_any

• rc == -1 for unrecoverable.
• rc == 0 for recoverable
• rc == len for success

Consistent return values / semantics by these functions would improve understandability.

There are some checks for impossible return values.

[pboothe]

Standardized things on write()'s semantics instead of on SSL_write()'s semantics. Updated write_raw and write_ssl.

[stephen-soltesz]

"git push"? There are no new commits atm.

[pboothe]

Yes, I got occupied by getting the unit tests to pass, which has required work because we changed mlab_builder's network connection. I'll send a PTAL when it is good to go.

[pboothe]

PTAL

[stephen-soltesz]

Completed second round of comments.

[pboothe]

PTAL

[stephen-soltesz]

Third round of comments complete.

[pboothe]

PTAL

[stephen-soltesz]

Thank you. LGTM.