Check if id field is not null and length is greater than zero.

git-svn-id: https://svn.code.sf.net/p/genoviz/code/trunk@15008 80d5a9c2-7d8c-4c9f-9369-4e03bca4d2bd
Handle cds seq symmetry.

git-svn-id: https://svn.code.sf.net/p/genoviz/code/trunk@15009 80d5a9c2-7d8c-4c9f-9369-4e03bca4d2bd
Check for cds seq symmetry in link control.

git-svn-id: https://svn.code.sf.net/p/genoviz/code/trunk@15010 80d5a9c2-7d8c-4c9f-9369-4e03bca4d2bd
Avoid unnecessary log messages.

git-svn-id: https://svn.code.sf.net/p/genoviz/code/trunk@15011 80d5a9c2-7d8c-4c9f-9369-4e03bca4d2bd
Merge remote-tracking branch 'upstream'