Fix bfGetReader for empty input

Convert isFake into anonymous function which is only called if an input
argument is supplied.

OME-DCO-1.1-Signed-off-by: Sebastien Besson <seb.besson@gmail.com> (github: sbesson)
Improve fake file detection

OME-DCO-1.1-Signed-off-by: Sebastien Besson <seb.besson@gmail.com> (github: sbesson)
Refactor bfGetReader input check

- First check for fake string
- Check for file existence using fileattrib()
- Remove unnecessary nargin==0 check

OME-DCO-1.1-Signed-off-by: Sebastien Besson <seb.besson@gmail.com> (github: sbesson)
Precise condition of lurawavelicense check

OME-DCO-1.1-Signed-off-by: Sebastien Besson <seb.besson@gmail.com> (github: sbesson)
merge dev_5_0 -D org: PR 1206 (Fix bfGetReader for empty input)
merge dev_5_0 -D org

Repository: openmicroscopy/bioformats
Excluded PRs:
  # PR 1213 emilroz 'Czi expand metadata to all the channels' (status: error)
Updating 0cb78d9..06f23c9
Merged PRs (fast-forward):
  # PR 1207 rleigh-dundee 'docs: Merge xsd-fu prerequisites into build instructions'

Merged PRs:
  # PR 1206 sbesson 'Fix bfGetReader for empty input'
Generated by OMERO-5.0-merge-push#104 (http://ci.openmicroscopy.org/job/OMERO-5.0-merge-push/104/)