Gns3-server

* Add debug message for what directory is checked for Qemu binaries. Ref 1655

* Fix AttributeError: Cannot set attribute '%s'. Fixes 1646

* Revert to jsonschema 2.6.0 due to packaging problem.

* Bump jsonschema to version 3.0.2
* List Hyper-V VMs on non-english OSes. Fixes 1612
* Add missing default values in Cloud schema.

* Requires a project to be opened to start/stop/suspend all nodes. Fixes 1609
* Fix issue when starting GNS3 VM for Hyper-V
* Set defaults for custom cloud nodes.
* Fix issue when trying to rename a Dynamips node that is already powered on. Fixes 2824
* Remove deprecated Qemu parameter to run legacy ASA VMs. Fixes 2827
* Add debug message when searching for an image. Ref https://github.com/GNS3/gns3-gui/issues/2828