[FIXED] Holding the @setenv restriction isn't preventing other objects from changing the environment settings

[FIXED] FIRE-30508: @setenv_XXX commands are non-functional when the shared environment is the currently selected environment

following promotion of DRTVWR-503

Enable/disable additions for @buy/pay restrictions + show a blocked notification whenever the floater would have opened to inform the user

Add @buy and @pay restrictions to block object purchases and avatar payments respectively (because of baguettes)

  -> Also prefer using isExiting() over isQuitting()

[FIXED] Assertion failure on m_Object.empty() in RlvHandler::cleanup() when an object only issues unknown commands
  -> In this case @nohax=n by an OpenCollar

SL-13830 Remade vivox shutdown to terminate when it is told to shutdown instead of when viewer is quiting

Got into D503 by accident

LN (EKU_TLS) is more likely to be present thus should be checked first

This reverts commit 92499ce1.

# Conflicts:
#	indra/newview/llinventorybridge.cpp
#	indra/newview/llinventorypanel.cpp
#	indra/newview/llinventorypanel.h

This reverts commit 25fd4c2b.