new test to check for dtype issues of grad
temporary fix of test (until new pr)
new implementation of grad method
fixed error 1
fixed error 2
fixed error 3
change names to more proper things
shared variables become sit_sot if are of tensor type
correction of grad method for DimShuffle
correction of grad method for RandomState
correct number of steps
handling disconnected and undiff cases
correcting rop2 test
new test for numeric shared
fixed error in structured text
allow providing dtype to safe_new
added comment about negative index
PEP 8 fixes
figuring out the right dtype
list of expandable types used by scan for shared variables