Added equal and notEqual operation between sparse matrices
Added support for sparse-dense matrices comparison, tests and updated documentation.
Added scipy version check
Modified version check
Renamed function eq and neq
Fixed comment
Added le, lt, ge, gt and associated test cases
Added documentation
made fixes and tweaks
fixed formatting
Fixed version check
Merge pull request #1851 from Hengjean/sparseComparisonOp

Added comparisons operators for sparse matrices