SL-18837: Boost.Bind _1, _2 placeholders are no longer global.

This was a longstanding complaint: that Boost shouldn't dump the (somewhat
mysterious) _1, _2 et al. names into the global namespace. Recent Boost has
fixed that, requiring 'using namespace boost::placeholders;' if you want to
use them unqualified.

indra/llinventory/llsettingsbase.cpp

@@ -31,6 +31,10 @@
 #include <algorithm>
 
 #include "llsdserialize.h"
+#include <boost/bind.hpp>
+
+// allow unqualified _1, _2 et al. to mean boost::bind placeholders
+using namespace boost::placeholders;
 
 //=========================================================================
 namespace

indra/llinventory/llsettingssky.cpp

@@ -31,6 +31,10 @@
 #include "lltrace.h"
 #include "llfasttimer.h"
 #include "v3colorutil.h"
+#include <boost/bind.hpp>
+
+// allow unqualified _1, _2 et al. to mean boost::bind placeholders
+using namespace boost::placeholders;
 
 //=========================================================================
 namespace

indra/llinventory/llsettingswater.cpp

@@ -32,6 +32,10 @@
 #include "llfasttimer.h"
 #include "v3colorutil.h"
 #include "indra_constants.h"
+#include <boost/bind.hpp>
+
+// allow unqualified _1, _2 et al. to mean boost::bind placeholders
+using namespace boost::placeholders;
 
 const std::string LLSettingsWater::SETTING_BLUR_MULTIPLIER("blur_multiplier");
 const std::string LLSettingsWater::SETTING_FOG_COLOR("water_fog_color");