New sparse gradient is returned, ADDSD is optimized in place, we have to write a flag to turn on optimization in case of updates
index the sparse matrices according to their format instead of converting them to coo, add a flag for inplace operation
first c code running in place addition
speed up sparse construct op by 9x
Merge branch 'master' of https://github.com/Theano/Theano into grad_advinc_subtensor
enable local inplace optimization and only works for the python version
C code now supports csr formats and no-in-place operations
Merge branch 'master' into grad_advinc_subtensor
Merge branch 'master' into grad_advinc_subtensor
Added comments to the code to document understanding of Gradient of Subtensor patch
Merge branch 'master' into grad_advinc_subtensor
Merging from LatestTheano
Merge branch 'trunk' into TheanoBugFix
better error message (and partial code clarification)
Fixed indentation in opt.py
Merge remote-tracking branch 'vivek/TheanoBugFix' into grad_advinc_subtensor
importing ssparse in constructor
Merge pull request #2 from viveksck/TheanoBugFix

Importing Scipy sparse in the ContructSparse Op to avoid unnecessary Scipy dependency.
Taken care of code review comments partially
Taken care of all comments