Fix startup crash when using a locale boost does not like

There are various locale related bugs in various versions of boost,
where exceptions are thrown in boost::filesystem APIs when the
current locale is not to boost's liking. It's not clear what "not
to boost's liking" means in detail, though "en" and "en_US.UTF-8"
are not to its liking.

Fix it by running a test function that's known to throw in such
a case, and resetting LANG and LC_ALL to C if an exception is
thrown. In simplewallet, the locale is queried before that so the
correct translations will still be used.

src/daemon/main.cpp

@@ -54,6 +54,8 @@ int main(int argc, char const * argv[])
 		_note_c("dbg/main", "Begin of main()");
 		// TODO parse the debug options like set log level right here at start
 
+    tools::sanitize_locale();
+
     epee::string_tools::set_module_name_and_folder(argv[0]);
 
     // Build argument description