Clean up predicate functors used with thrust transforms.

Obsolete 'NotTrue' (use thrust::logical_not instead)
Move ExpOp in graph.h and remove its template parameter as it is always working on doubles.
Remove various variants of the graph::dropOff() functions.

Obsolete the version using 'dropMin', as well as dropOffPost().
Fix various compilation warnings.

Changes meant to address loss of precision due to conversion
and forcing of int to boolean warnings.
Add optional solver input to specify the maximum half-bandwidth.
Merge branch 'develop' of https://github.com/spikegpu/SpikeLibrary into feature/drop_off
Another related to conversion warnings.
Implement new drop-off algorithm.

Drop-off is now based on the element-wise 1-norm of the banded matrix
and includes an overriding optional maximum bandwidth.
Merge branch 'feature/drop_off' of https://github.com/spikegpu/SpikeLibrary into feature/drop_off
Merge branch 'feature/drop_off' into develop