Ec2 masternode root account changes

[David Suárez <david.sephirot@gmail.com>]

Hi,

From now, logins on masternode using root account, is forgiven.

If you need access, you can contact me to add a new account. Please, send me 
the desired login, I will use the current old ssh keys of the root account. If 
you want to change them, attach a new ones.

Please, it would be good to start to using the '-d' flag of masternode script 
to avoid conflicts beetween users. It changes the build-logs output dir (see -h 
for help).

Thanks, and sorry for the incoveniences that this change can cause.

David