changed std::string into RsFileHash for all file hashes

git-svn-id: http://svn.code.sf.net/p/retroshare/code/branches/v0.6-IdCleaning@7137 b45a01b8-16f6-495d-af2f-9b41ad6348cc
fixed a few small issues with ids

git-svn-id: http://svn.code.sf.net/p/retroshare/code/branches/v0.6-IdCleaning@7138 b45a01b8-16f6-495d-af2f-9b41ad6348cc
group id refactoring done for librs
- now on to messages
- need to test at this check point (need to convert test and gui tho)

git-svn-id: http://svn.code.sf.net/p/retroshare/code/branches/v0.6-IdCleaning@7139 b45a01b8-16f6-495d-af2f-9b41ad6348cc