Fix issue #520: Allow null to be used to omit Diet template attributes
add way to set sslValidation for smtp connection in sendMail
fix typo
Missing import of 'std.string.format' and 'std.traits.fullyQualifiedName' in static assert.
Merge pull request #529 from Extrawurst/patch-4

fix typo
Merge pull request #531 from Geod24/fix-missing-import

[Trivial] Missing import in static assert
Updated the log[Info|Error|...] functions to take any string.

Before they only accepted string.
Merge pull request #532 from Geod24/fix-logfunctions-types

Updated the log[Info|Error|...] functions to take any string.
Avoid creating putting LockedConnection instances on the heap when not necessary. Fixes #530.

Also drops the use of format() in favor of formattedWrite() in _request_simple to avoid memory allocations.
Merge pull request #528 from Extrawurst/master

add way to set sslValidation for smtp connection in sendMail
Avoid double-closing the TCP connection in HTTPClient.disconnect().

See rejectedsoftware/dub#250 and rejectedsoftware/dub-registry#44
Continue closing a TCP connection if an exception occurs while draining the output buffer.

See rejectedsoftware/dub#250 and rejectedsoftware/dub-registry#44
Merge pull request #521 from nazriel/issue520

Fix issue #520: Allow null to be used to omit Diet template attributes