[reSIProcate] minor changes (vector and HashMap)

[Jason Fischl]

I  made some changes in the following files to use HashMap instead of  
std::map. On Windows, this is still std::map but on g++ systems it will 
use the hash_map class.

Contents.cxx/hxx
- note I also checked in some code to cleanup the Contents from the 
ContentFactory on shutdown

Mime.cxx/hxx
- added a Hash operator so Mime types can be put in hash tables

SdpContents.cxx/hxx
- use std::vector intead of std::list
- use HashMap instead of std::map

Log.cxx/hxx
- use HashMap instead of std::map