implement http api in a separate thread
some refactoring and new signal for strategy unload
ensure application wide unique increaing nonce with locking
resend http if error
Revert "disable "Invalid-call"-workaround, might finally be fixed."

This reverts commit c074fb8300eef96ece79fceecdfdcddd458ebc4a.

Conflicts:
	goxapi.py

fixed above conflict (so its not 100% identical inverse patch)
and also fix a small error from previous commit.