Update POMs to point to mirror of the cppwrap plugin

This removes the dependency on maven.imagej.net, which has been causing
problems for Travis and Jenkins.
UpgradeChecker: fix the stable version number

Fixes #11865.
ant: release target archives release version metadata

tools/source-archive creates and repacks the source release,
and embeds ant and cmake version metadata in the release.
ant/version.xml conditionally includes ant/gitversion.xml,
overriding the use of git when building from a source
release.  This file will never be present in a source
repository.
CoreMetadata: update copying constructors to initialize Modulo values
Allow one Modulo annotation of each type for every Image

Previously, only one ModuloZ, ModuloC, and ModuloT was allowed across
the board, which meant that multi-Image datasets could not use a
different Modulo definition for each Image.
cpp: cmake uses embedded version metadata
Flex: be more permissive in parsing IFDs and XML

This allows a trailing ">" in the XML block, in addition to forcing more
thorough IFD parsing when the images are stored before the IFDs.

See
http://lists.openmicroscopy.org.uk/pipermail/ome-users/2014-January/004164.html
ant: release target works when run in a submodule

Check for presence of .git, not whether it's a directory.
Fix tiled TIFF saving when partial tiles will be used

If the image width and/or height are not multiples of the tile
dimensions, then the last tile in each row or column will be smaller
than the others.  This commit prevents an exception when that is the
case.
Restrict direct tile copying to single-tile images
Initial version of bfCheckJavaMemory

This displays a warning message if the heap space is below 512m.  Only
functions that call setId currently call bfCheckJavaMemory.
Update copyright year
Allow the minimum memory value to be specified

The default value is still 512m.
bfCheckJavaMemory: fix typo in function definition
bfCheckJavaMemory: use 'warning' instead of 'fprintf' for logging
Change warning ID from 'bf' to 'BF:lowJavaMemory'

...as suggested by @sbesson.
Add unit test class for bfCheckJavaMemmory() function
Combine warning messages to have one warning with specified ID
Implement pre-loading for .sdt files in the interest of performance as an option.
Extend pre-load option to allow smaller sub-planes & address format issues.