Patches for SERVER-1268, fully qualifying std:: symbols in headers visible to clients

Hi,

  This fixes SERVER-1268; it's fairly mechanical, but unfortunately touches a lot of files. Applying the first patch and doing:

    scons smokeClient

will recreate the problem. 

  The client test does not try to alias /all/ std:: symbols (and this patch might miss some), just all the more common ones that I noticed in the headers. Also, to keep the patch limited to 1268 it does not fully qualify std:: symbols in all /headers/, though that wouldn't be too much more work; but, only in those headers visible to clients, via #include "client/dbclient.h". It also removes 'using namespace std' from one of the headers, I don't recall now which. 

  I didn't do anything with symbols that could be either in boost or c++0x, like shared_ptr, mutex, or thread. 

  Besides qualifying the symbols it also adds the appropriate std:: header if not already present, so that each mongo header is as self-contained as possible. (ie reduces instances of .h files which use eg vector, without #include-ing \<vector\> itself but relying on it being included by some previous header). 

  The 3rd patch is a perl script '1268.pl' in the root, that does the hard work. It's 95+% correct (unnecessarily adds std:: in comments; also in util/log.h there are an endl and hex defined that are local and should not be prefixed). 
Thanks.