With any luck most of the linux build issues should be addressed in the next release.
Gjor: That function is implemented in logindatabase.cpp in the login directory--should only be required if you're trying to build a full login server.  I didn't run across it so it might have been fixed already.  If you still run into it w/the next release, post the file it's happening in, & it can be addressed.
Trumpcard:  Instead of prefacing dec & hex w/std:: see if adding "using namespace std;" to the top of the affected cpp files after the #include statements will take care of things.  It's actually a bug w/glibc's headers as dec & hex should be imported given we're including the old style iostream.h--free stuff can't always be perfect I suppose.  

  Should save you a bit of work, & if it doesn't break other gcc versions we could roll it in at some point.