Rewrite to move away from PEAR packages - Mail_mimeDecode

[pestevao]

Hello,

I've just installed MailZu from this fork, thank you for not letting this usefull piece of code die!

In this procces I have realised that there is another PEAR package needed - Mail_mimeDecode - that haven't see referenced in docs/INSTALL under requirements.

Greetings, Pedro

[gnanet]

Current developments included the reference to Mail_mimeDecode in INSTALL, but the plan is to rmove away from Pear Mail and Mimedecode and use for example mailparse extension