backport SConstruct patch 8f93e0ebb01a2cccafa45f851dd18dc660f94176

This is to assist package managers trying to build the project, by
giving them a diff they can refer to.
Merge branch '1.10.7_scons_patches' into 1.10
fix an uncaught bad lexical cast exception

coverity reports that it is uncaught and would therefore crash
the server if it occurred
replace many lexical_cast with lexical_cast_default

This is to avoid bad_lexical_cast exception. I'm not sure if in
any cases this could actually have thrown but it's better to be
safe.

Conflicts:
	src/server/game.cpp
catch boost::bad_function_call exceptions in server command handler

Don't know if this can actually happen in practice but it is
reported by coverity.
server: catch invalid utf8 exceptions

issue reported by coverity

Conflicts:
	src/server/ban.cpp
	src/server/server.cpp