fix stuff found by cppcheck

almost 3000 lines of "errors" contained one actual memleak, one actually
unused variable and three actual ambiguous code parts

from cppcheck website: "The goal is to detect only real errors in the
 code (i.e. have zero false positives)." :)

thx for finding five problems in our code

source/src/tools.cpp

@@ -30,7 +30,7 @@ const char *timestring(time_t t, bool local, const char *fmt, char *buf)
     return buf;
 }
 
-const char *asctime()
+const char *asctimestr()
 {
     return timestring(true, "%c");
 }