Re-organise shared folders

config including ssh private keys for emulators/devices and devices.xml :

<QtC_sdk>/vmshare/ssh/private_keys/*/	private keys to ssh to emul
<QtC_sdk>/vmshare/devices.xml		device description/config

<QtC_sdk>/vmshare is shared as 'config' to MerSDK and emulators mounted under
/etc/mersdk/share

Engine Targets/ssh:

<QtC_sdk>/mersdk/targets/*/		Targets
<QtC_sdk>/mersdk/targets/targets.xml	Target description
<QtC_sdk>/mersdk/ssh/*/ 		authorized_keys for sshd

<QtC_sdk>/mersdk/targets is shared as 'targets' to MerSDK mounted under
/host_targets/
<QtC_sdk>/mersdk/ssh is shared as 'ssh' to MerSDK mounted under
/etc/sshd/authorized_keys

Emulator ssh
<QtC_sdk>/emulator/1/ssh/*/ 		authorized_keys for sshd

<QtC_sdk>/emulator/1/ssh is shared as 'ssh' to MerSDK mounted under
/etc/sshd/authorized_keys

Signed-off-by: David Greaves <david.greaves@jollamobile.com>
Add some usage on the options

Signed-off-by: David Greaves <david.greaves@jollamobile.com>
Add -p to specify projectdir and tidy up whitespace

Signed-off-by: David Greaves <david.greaves@jollamobile.com>
preliminary devices support

Signed-off-by: David Greaves <david.greaves@jollamobile.com>
Setup SDK LAN with both ethernet interfaces; do it before connman comes up but after shared folder

Signed-off-by: David Greaves <david.greaves@jollamobile.com>
Remove default unit. Setup correct [Install] sections

Signed-off-by: David Greaves <david.greaves@jollamobile.com>