drugdata/D3R: Enabled custom smtp configuration

Breaking change Added new flag to celpprunner.py --smtpconfig that lets a user specify smtp configuration information. At the same time removed --replyto --smtp, and --smtpport since those options would be confusing to have also in place. Issue #166

molfilevalidator.py has new command line option --excludedir to let caller ignore directories when looking for mol files. Issue #167

Fixed bug where a network hiccup raised an exception during DataImportTask causing celpprunner.py to exit prematurely. Issue #168

Improved error message output when a participant uploads a malformed challenge data package. Issue #169

Version of D3R is now output in post evaluation summary email. Issue #172

Fixed bug where celpprunner.py was not sending an email to people in --summaryemail list if a task fails. Issue #171

Post evaluation summary email now outputs lines with NA values for any submissions that failed. Issue #130