M #-: Adapt to latest generateDS (OpenNebula#3917)

(cherry picked from commit ace990c)

B OpenNebula#3167: Fix bugs (OpenNebula#3991)

Signed-off-by: Jorge Lobo <jlobo@opennebula.systems>

M #: Minor fix for docker-machine add-on (OpenNebula#3926)

B OpenNebula#3832: preserve attributes vmtemplate (OpenNebula#3843)

Signed-off-by: Jorge Lobo <jlobo@opennebula.systems>

B OpenNebula#3174: Fix response for calculateshowback (OpenNebula#3718)

B OpenNebula#3195: fix bug position elements (OpenNebula#3539)

Signed-off-by: Jorge Lobo <jlobo@opennebula.systems>
(cherry picked from commit 1194eb4)

B OpenNebula#3430: Do not return tainted key reference

If the element to be retrieved from the vCenter cache does not
have a reference, return nil, and not a tainted vCenter uuid reference

(cherry picked from commit 4767556)

B OpenNebula#3326: Do not set mac when importing template (OpenNebula…

…#3327)

(cherry picked from commit d936158)

F OpenNebula#3167: Add User-Agent for enterprise and GH reqs

(cherry picked from commit 3e1d571)

Update ec2 instance types (5.8 release)