[RLVa] rlva strings floater!

Generalized toggle() visible() call pattern of rlv floaters to a template struct.
[RLVa] Version 1.4.9

Thanks to Trinity and, of course, her Kitty!
Translations fix ups
Feature request: menus on the region estate panel's scroll lists.
Group Feature Request: Option to Copy SLURL for an avatar's profile

Added to avatar list menus and instant message drop down menu.
Fix Issue 1237: Last online says 01/01/1970 for group members

For real this time!
Support the Script Message API
Fix the Login Panel such that it persists until a successful login and maintains ui values between failed logins

When the login panel used to die, it now hides instead, we only truly kill it upon successful login.
Much of the opening and setting behaviors have been cleaned up to ensure fields are autofilled by the viewer without any user action once
Everything else like changing saved logins will still work the same.
Address Issue 1371: Enhancement: in Edit object Positions X & Y for OpenSim VarRegion