permit VCell client installation without admin privileges

[jcschaff]

The agility of the software development process is hampered by the requirement for some end users to have administrative privilege to their machines, thus requiring calls to admin support for some institutions. This applies pressure to the VCell team to refrain from updating the client very often (and therefor not updating the software at all).

VCell client should be made to not require admin privileges if possible and the update process streamlined.