Reframe 2.5 release notes

API changes

sourcesdir may now be None in which case the regression test is resourceless

Treat properly stage and output directories if they alias each other
Improvements of the internal launcher API to allow users to create custom launchers
Addition of a VisitLauncher for the VisIt visualisation software
Support for custom execution modes
--notimestamp and --timefmt options replaced by a single --timestamp TIMEFMT option; no timestamp directory components are appended anymore
Bug fix: crash when printing system listing and the current system was not auto-detected
Bug fix: Environment names with slashes are now treated correctly
Bug fix: asynchronous execution policy unit tests are now more robust
Bug fix: job launcher options were not emitted in the job script file