Made some float* parameters const

Change-Id: Ic15b7892ed0b07d2e0acba8b8b28758307b63cc8
Changed method declarations slightly from * to [] style

The explicit size gives the user more information as
to acceptible values.

Change-Id: I7baa5dbca7f1b6edbb67ca3139abefea6aebd02f
Added const to a few more APIs

Change-Id: I54d1c6d87be3131e5418f919acb5a629347c894c
Merge topic 'const-improvements' into master

e17528fd Added const to a few more APIs
37c1e4a7 Changed method declarations slightly from * to [] style
ed664cec Made some float* parameters const
ENH: Update vtkDelaunay2D to support DesiredOutputPrecision

This updates vtkDelaunay2D to support a choice of desired precision
(default, single, or double) for output points. It uses the analogous
code in vtkThreshold as a model.

Change-Id: Ib5d9149f5bb34fc4be0b5005b0e94e38fcf5b52b