Prevent empty StructuredAnnotations from being created

If Modulo annotations and original metadata are not present, there is no
need to create a StructuredAnnotations object.

Fixes #11867.
Leica .lei: fix file matching when there are multiple candidate series

This prevents a series with missing files from picking up files that
belong to a subsequent series.

Fixes #11683.
APNG: eliminate need for deinterleaving

By setting the 'interleaved' flag differently, the deinterleaving logic
can be removed, which prevents the reader from allocating another image
array.  This improves performance and memory usage for larger images.

Fixes #10796.
Prevent misleading IOException during config file parsing
FV1000: populate DeltaT based upon the start/end times

Fixes #11087.
APNG: fix tile pasting for images beyond the first
FV1000: parse position data from .pty files

This is a slightly modified version of the patch submitted by Patrick
Riley in this mailing list thread:

http://lists.openmicroscopy.org.uk/pipermail/ome-devel/2014-March/002696.html
Resolve model references even if annotations are not populated

This should fix #12093.
Merge pull request #1000 from melissalinkert/metadata-fixes

Metadata fixes