start to add a c++ version of lbfgs
more work on lbfgs_cpp.

the structure is done and it compiles, but it's not fully working yet
small changes
more work on lbfgs_cpp

nearly there, but there is still a bug
lbfgs_cpp now works

the last bug was I was assing y and s incorrectly
rename files in native_code

from pygmin to pele
move c lbfgs
copy c++ version of lbfgs into pele
start to get c++ lbfgs to work in pele
some work on lbfgs_cpp

I can't quite get it to work
fixed native code issue
some tuning
removed old files from native
remove old files that have been replaced
add a verbosity flag to lbfgs_cpp
add cython generated .cpp files
undo changes victor accidentally committed last night
pgorder and zero modes in aasystem
added back functionality in disconnectivity graph to lookup node by minima
removed redundant N_ in native lbfgs, cleanup, improved interface