Remove hard-coded Bio-Formats version check in bfGetPlane

loci.common.DataTools.makeDataArray2D is now present on all branches so there
is no need to check the version of Bio-Formats. Sign and typecast conditional
tests should be sufficient to switch between both methods.
Fix bfGetPlane for signed pixel types

- Pass the correct input width variable to makeDataArray2D
- Rename arr variable as I to avoid matrix duplication
Improve bfGetPlane header
Add additional input check to bfGetPlane()

- Add basic validators for plane index as well as tile coordinates.
- Add corresponding unit tests to TestBfGetPlane
Refactor TestBfGetPlane to store function input as class attributes
Add check for reader validity and corresponding unit test
Add additional input check for invalid tile size

- Add corresponding test to TestBfGetPlane
Merge pull request #631 from sbesson/bfgetplane_fix

bfGetPlane fix and hardcoded version removal