Doxygen atomic namespace
MVNORM: Use atomic matrix AD by default
- flag added to disable atomics.
- only one example runs slower with atomics (sdv_multi).
- special atomic 'invpd' added to get both inverse and logdet of pd matrix.
- include order rearranged: had to split tmbutils.cpp.
atomic matrix multiply generalized to non-square matrices.
Bias correction option to sdreport (epsilon method)
    - Fix bug in 'sdreport' when ad-reporting mulitple values with only one fixed effect.
    - sdreport interface to bias correction
    - Prepared C++ part of epsilon method (Note: Not currently adapted for parallel runs).
    - Avoid crash when augmenting parameter vector with parameters not used by template
    - Extend importance sampler to calulate mean of any function,
importance sampler value and gradient: fix nan issue and optimize
Parallel runs: Reduce memory
- Avoid calling optimize in parallel
Control remaining tape optimization calls.
- Can now disable _all_ optimization with config(optimize.instantly=FALSE)
CppAD: Apply changeset_3494.diff
gdbsource on windows
    - install_windows: Added gdb to PATH and locate Rterm.exe
    - gdbsource: stop if file not found
    - gdbsource documentation
make doc-update
Disable CppAD optimization of conditional expressions (CSkipOp) by default
    - A bug was introduced when upgrading to recent cppad version.
      The bug affected examples using CppAD::CondExp (e.g. 'posfun').
      It is now fixed in CppAD and the fix has been merged into TMB.
    - For safety, we disable this optimization by default until the feature has been better tested.
    - To enable CSkipOp (for testing) add '-DTMB_ENABLE_CSKIPOP' to the pre-processor.
    - TODO: Add tmb_example that use conditional expressions (so that issues like
      this are caught by the automated tests in the future).
Merge pull request #68 from kaskr/testing

Testing