Added bundler.py to replace the existing RunBundler.sh bash script.
The Python script reduces the number of dependencies required by
the project, offers a parallel mode for extracting SIFT features,
and (should) increase portability (no more dependence on bash, ...).
bundler.py can be run to produce similar output to RunBundler.sh
(also just as slow):

  > bundler.py --verbose --no-parallel
Merge branch 'PyRunBundler' of https://github.com/ilent2/bundler_sfm
Merge branch 'master' of github.com:snavely/bundler_sfm
inlining a couple matrix functions
various fixes / cleanups to code
Readding RunBundler.sh with the ability to read a config file
adding back in scripts used by RunBundler.sh
edits to .gitignore
removing empty BundlerYaba.cpp
adding in_front return value in sfm-driver code
adding BundleCeres.cpp
small typo fixes to bundler.py
moving bundler.py to utils directory
moving bundler.py to utils directory
adding support for Ceres / cleaning up code some more
adding snavely_reprojection_error file for Ceres
minor edits to bundler.py
updating README
playing with Ceres radial distortion weights
more edits to README