Re #1567: readEeprom():
 * added PID to temporary file name
 * better error message
 * temporary file deletion
Re #1567: writeBackup(): added PID to temporary file name
Re #1567: introduced unlink() function that takes QString parameter
Re #1567:
introduced generateProcessUniqueTempFileName() which is used everywhere we need temporary file
renamed unlink() into qunlink()
fixed missing deletion of curve pngs in print dialog
Re #1567: cleanup
Merge pull request #1586 from opentx/projectkk2glider/issue_1567

Projectkk2glider/issue 1567