Issue 96: Add Send Email Message Command

[Nightsphere]

This has the initial changes for the SendEmailMessageCommand. It can send an email using a pgpass-like file for Gmail authenication. It can also use CC, BCC, and an attachment file. I tried multiple attachments but the GUI seemed to only accept one file at a time for the moment, and I'll have to look into that more in the future.

As of these changes, only Gmail accounts can be used to send messages. I have added a simple create-mailpass.sh bash script in the scripts folder that will write the Gmail account ID and password in the user's home directory to .mailpass. The script usage would be similar to the following:

./create-mailpass.sh nightsphere88@gmail.com password12345

where the two arguments given are account ID and the password. Once that's done, when the SendEmailMessageCommand is run, it will read from .mailpass and authenticate accordingly. There's also basic usage help when running the bash script, but can be made more robust later.

[Nightsphere]

I suppose I don't make another pull request and I just let you know that another push was sent to my 96-send-email-command branch with the new changes. I worked mostly on the JavaAPI tab. The documentation was also pushed, so there should be a pull request for that as well.