Merging changes of r15400-15404. Version update, updated felix (v4.2.1) and fix for static accession warnings.

git-svn-id: https://svn.code.sf.net/p/genoviz/code/trunk@15405 80d5a9c2-7d8c-4c9f-9369-4e03bca4d2bd
Fixing use of == on string.

git-svn-id: https://svn.code.sf.net/p/genoviz/code/trunk@15406 80d5a9c2-7d8c-4c9f-9369-4e03bca4d2bd
Avoid comparing collection size to zero, instead using isEmpty.

git-svn-id: https://svn.code.sf.net/p/genoviz/code/trunk@15407 80d5a9c2-7d8c-4c9f-9369-4e03bca4d2bd
Using String.length() == 0 instead of comparing it to empty string.

git-svn-id: https://svn.code.sf.net/p/genoviz/code/trunk@15408 80d5a9c2-7d8c-4c9f-9369-4e03bca4d2bd
Use string buffer append when possible.

git-svn-id: https://svn.code.sf.net/p/genoviz/code/trunk@15409 80d5a9c2-7d8c-4c9f-9369-4e03bca4d2bd
Replacing instances of assignment operations by operator-assignment. It makes code clearer and theoretically more performant.

git-svn-id: https://svn.code.sf.net/p/genoviz/code/trunk@15410 80d5a9c2-7d8c-4c9f-9369-4e03bca4d2bd
Merging changes of r15411. Use isGraphTier to determine is it was really a graph or not.

git-svn-id: https://svn.code.sf.net/p/genoviz/code/trunk@15412 80d5a9c2-7d8c-4c9f-9369-4e03bca4d2bd
Merging changes of r15413. Updating error message to check for too many files.

git-svn-id: https://svn.code.sf.net/p/genoviz/code/trunk@15414 80d5a9c2-7d8c-4c9f-9369-4e03bca4d2bd
Merge remote-tracking branch 'upstream'