Included sprse testing functions test_sparse_classification() and test_sparse_regression() in test_weighted_boosting.py, based on the corresponding testing functions found in test_bagging.py
Removed densification calls on X  '.asarry()' from all predict methods, removed 'dense' parameter from check arrays call, removed contiguous cast of the input array X, detected X as list or array to find the number of examples accordinly using len() or shape[0]
In functions def test_sparse_classification() and test_sparse_regression() added tests for coo, lil, and dok sparse matricies. Removed parameter set feautre since there are not parameters that alter sparse/dense data usage. Revised data set to use dataset.make_{regression/classification} for improved test time.
Revised recuring import statement to respect conventions
Updated documention to reflect sparse support on input data
Removed prints statements used for debugging
Revied test_sparse_{regression,classification} to use make_multilabel_classification, revised import statements to adhere to one name per import conventions
Enforced dtype for X, and clarified documentation by indcating the sparse formats supported and how they are treated
Re inserted the check for X.ndim == 2 in initialization, updated a doc detail for X: coo is converted to csr only in the initialization not in the predict functions
Inserted base classifier check for BaseDesicionTree and and BaseForest before enforcing DTYPE in wieghted boosting fit
Resolved python3 forest import error in weighted_boosting.py
Updated documenation for weighted_boosting fit() to indicate behavior of forced dtype
Included testing of the all of the predict/score functions of AdaBoost
Assert sample weight negative sum value error, add authors entry
Fix score function parameter mistake in test_weighted_boosting
Remove exectuable permision bit
Fixed typo toCSR -> tocsr
Trivial doc alteration, travis timeout
Fixed paramaters to make_multilabel_classification and make_regression to keep tests under 1 second, reformated some blank lines
Merge pull request #3161 from hamsal/ada-sparse

[MRG] AdaBoost Sparse Input Support