[reSIProcate] major directory reorg

[Fischl jason <jason.fischl@xxxxxxxxx>]

While in Dallas we've discussed a major reorg of the directory
structure for resip/dum/repro/msrp. Here's the plan:

Current: 

resip:
main/sip/resiprocate
            /resiprocate/os
            /resiprocate/dum
            /resiprocate/dum/doc
            /resiprocate/dum/test
            /resiprocate/test
            /resiprocate/doc
            /repro
            /contrib

msrp:
main/src
main/doc

Proposed
Each of resip, rutil, repro, dum, contrib will be a different
repository. Here's roughly what the intermodule dependency is. We'll
use symbolic links (in svn) to satisfy the intermodule dependencies.
If you check out repro, it will check out the appropriate dependent
modules through the sym links.

                                           repro
                                              |
                       |---------------|--------------------------|
                    dum      contrib/db         contrib/pcre
                       |
                    resip                 
                       |
     ----------------------------------
     |                                |
  contrib/ares                 rutil

resip:
main/src/resiprocate
main/src/test
main/doc

rutil:  // resiprocate util
main/doc
main/src/rutil
main/src/test

repro:
main/doc
main/src/repro
main/src/test

dum:
main/doc
main/src/dum
main/src/test

contrib:
main/contrib
main/contrib/ares
main/contrib/db
main/contrib/pcre
main/contrib/dtls
main/contrib/getopt

Implications: 
- break out common utilities into rutil as a separate library. 
- Eliminates the os subdirectory -> will require mods to apps
- Moves dum to its own module instead of subdir of resiprocate -> will
require mods to apps
- symlinks are only supported in subversion >= 1.1