attachment/email handling improvements"

In the sales order, there is no ability to drag and drop attachments like in tasks or in the customer details:

It is a bit of a pain to have to locate the file to upload it, in particular if it is an email attachment, because I have to save it to a folder and then select it rather than just drag and drop.

In the sales order email templates, there is no way to drag and drop attachments:

If I amend the email and then realise the attachment is not in the list, then I have to go out of the email. If I’ve made any changes to the email, they won’t save. 

Emails for sales orders cannot be saved in draft:

Further to (2) above, it would be good if sales order emails can be saved in draft.