[check] Exception FindFailed: last successful match and last screenshot should be accessible

[RaiMan]

more a feature request: (updated after 0.10 released)

especially for long running, unattended scripts its vital, to have as much information available in case of FindFailed.

After an unsuccessful find getLastMatch() returns None. the lastMatch() should be left untouched, to be available in these cases.

On top, if there would be a (maybe limited) stack like region.findHistory (accessible with a region.getHistory() returning a list of matches), where the last successful match would be pushed in, you would have access to what happened in case of failure, without additional coding in the script.

in case of FindFailed the last screenshot should be available. (additional option saveScreenshotAtFindFailed("path-to-a-file"))