#131 vendor extension commands

[Andrzej Adamczyk]

Hi,

Libmtp is an awesome library for its standard usage.
But there is a lack of very useful feature: sending custom commands.
Can you please consider to extend libmtp API - libmtp.h to let the user to define and send custom vendor extension commands.

For example in my application I need to send custom vendor MTP commands for some specific tasks.
On Windows I'm using WPD IPortableDevice::SendCommand. But my application needs to be ported to Mac OS so I found that libmtp would be the ideal candidate - until I found that it cannot send custom mtp command.

I've noticed that the generic MTP sending in libmtp is done by filling the PTPContainer params and use "ptp_transaction_new" function defined in ptp.h.
Unfortunately there is no way to access to these functions from the libmtp.h API's.

Thank you in advance for considering this