Update CONTRIBUTING.md
Merge pull request #148 from mbouaziz/master

Enhanced xml parsers
Update README.md
[fix] stdlib:  Respond Ok to empty command for SmtpServer.
[fix] mongo:  Arrange for authentication of fresh sockets from socket pool
[enhance] DbGen: add case insensitive regex operator =~

  * Mongo supported, not postgres
[feature] DbGen:  Export dbgen's mongo setup for use by backup code
[fix] mongo:  Disable mongo socket pool authentication due to problems with GridFS
[feature] System.execo: exec with options (timeout, maxBuffer, cwd, killSignal)