Handle ssh keys as objects, not strings, and improve the ls and rm key commands
"gitblit keys ls" now defaults to showing an indexed list of fingerprints which almost matches the output of "sshadd -l". The indexes are useful specifying key(s) to remove using "gitblit keys rm <index>". This is an important improvement for key management.
issue-361: Reset user cookie after administrative password change
Cookies were not reset on administrative password change of a user
account. This allowed accounts with changed passwords to continue
authenticating. Cookies are now reset on password changes, they are
validated on each page request, AND they will now expire 7 days after
generation.