Coverity fixes.

The Boost UUID random generator can throw an entropy error in the KIID
object constructor which leaves the UUID generator in an undefined state.
This is treated as a fatal error and KiCad is closed.  The likelihood of
this occurring is low but at least now it is properly handled and cannot
result in UUID clashes.

Reports 305311, 305372, 305492, 314743, 314754, 314757, 316277.

common/kiid.cpp

@@ -30,6 +30,13 @@
 #include <boost/uuid/uuid_io.hpp>
 #include <boost/functional/hash.hpp>
 
+#if BOOST_VERSION >= 106700
+#include <boost/uuid/entropy_error.hpp>
+#endif
+
+#include <wx/log.h>
+
+
 // Create only once, as seeding is *very* expensive
 static boost::uuids::random_generator randomGenerator;
 
@@ -40,6 +47,7 @@ static boost::uuids::nil_generator    nilGenerator;
 // Global nil reference
 KIID niluuid( 0 );
 
+
 // For static initialization
 KIID& NilUuid()
 {
@@ -48,8 +56,25 @@ KIID& NilUuid()
 }
 
 
-KIID::KIID() : m_uuid( randomGenerator() ), m_cached_timestamp( 0 )
+KIID::KIID()
 {
+    m_cached_timestamp = 0;
+
+#if BOOST_VERSION >= 106700
+    try
+    {
+#endif
+
+        m_uuid = randomGenerator();
+
+#if BOOST_VERSION >= 106700
+    }
+    catch( const boost::uuids::entropy_error& e )
+    {
+        wxLogFatalError( "A Boost UUID entropy exception was thrown in %s:%s.",
+                         __FILE__, __FUNCTION__ );
+    }
+#endif
 }
 
 
@@ -87,7 +112,21 @@ KIID::KIID( const wxString& aString ) : m_uuid(), m_cached_timestamp( 0 )
         {
             // Failed to parse string representation; best we can do is assign a new
             // random one.
-            m_uuid = randomGenerator();
+#if BOOST_VERSION >= 106700
+            try
+            {
+#endif
+
+                m_uuid = randomGenerator();
+
+#if BOOST_VERSION >= 106700
+            }
+            catch( const boost::uuids::entropy_error& e )
+            {
+                wxLogFatalError( "A Boost UUID entropy exception was thrown in %s:%s.",
+                                 __FILE__, __FUNCTION__ );
+            }
+#endif
         }
     }
 }
@@ -211,4 +250,4 @@ wxString KIID_PATH::AsString() const
         path += '/' + pathStep.AsString();
 
     return path;
-}
+}