refactor cachedop

[piiswrong]

@sergeykolychev I refactored CachedOp and revered changes in perl.

[sergeykolychev]

@piiswrong are you ok with me just redoing the cachedop for Perl to make it compatible with your changes without​ yanking whole pull away ?

[sergeykolychev]

On other hand the errors in the Perl tests are superficial , no tests failed just the number of tests run need adjustment , I will create a pull against this pull with the tests fix and will worry about the cachedop later. Do you plan to redo it or you consider it's stable this time ? I'll wait with porting of your changes if it's still in flux. Thanks

[sergeykolychev]

@piiswrong piiswrong#4 this fixes the perl tests on this branch.

[piiswrong]

I only removed the cachedop for perl.

Its probably better to wait for a couple weeks before reintroducing it to perl.

Thanks

[sergeykolychev]

Ok, sure, I'll wait.

[sergeykolychev]

@piiswrong looks like my test number fix got somehow removed from your branch, you'll need to reapply.