ADDED busy flag to REIXSScanActionControllerMCPFileWriter::writeToFile()
Hopefully will resolve intermittent crash on cancel.
ADDED busy flag to REIXSScanActionControllerMCPFileWriter::writeToFile()
    But actually saved changes this time...  Hopefully will resolve
intermittent crash on cancel.
Added a comment to the member variable and added the underscore at the end.
Merge pull request #1011 from acquaman/Issue1007

Simple change only affect REIXS and appears to work.