Synchronize get track method.

git-svn-id: https://svn.code.sf.net/p/genoviz/code/trunk@15796 80d5a9c2-7d8c-4c9f-9369-4e03bca4d2bd
Changing disable icon.

git-svn-id: https://svn.code.sf.net/p/genoviz/code/trunk@15798 80d5a9c2-7d8c-4c9f-9369-4e03bca4d2bd
Avoid concurrency error.

git-svn-id: https://svn.code.sf.net/p/genoviz/code/trunk@15800 80d5a9c2-7d8c-4c9f-9369-4e03bca4d2bd
Merge remote-tracking branch 'upstream'