Added support to prompt for support case for RH Dropbox log collection

- Changes to prompt with JS pop up box for support case when file_log_depot type is "FileDepotFtpAnonymousRedhatDropbox".
- Changed logs_collect method to pass support_case in options that is being store in args column of miq_queue table.

https://bugzilla.redhat.com/show_bug.cgi?id=965889
Merge pull request #288 from h-kataria/support_case_alert_box_changes

Added support to prompt for support case for RH Dropbox log collection
Remove Support for VixDiskLib 5.1.0

VixDiskLib 5.1.0 has a known bug intermittently causing a
segfault during disk open operations when the vCenter Server
does not provide an SSL thumbprint for the target host.  The
error depends upon the memory content.  This segfault has been
encountered during testing so support for this version has
been removed.  Only this version has this flaw.