Allow to load ".set" files, which aggregate a set of coverage files

[zxgio]

This patch allows loading the result of the intersection/union/subtraction of a set of coverage files. A (text) ".set" file consists of a line with the desired operations and the list of coverage files to aggregate.

[oddcoder]

can you please add a unit test for that ?

[oddcoder]

ping @zxgio

[zxgio]

Hi @oddcoder , sorry for the delay; in a couple of weeks, I'll try to refactor my code and add unit tests. Now I'm working overtime for a job-related deadline.

[oddcoder]

ping @zxgio

[zxgio]

I have refactored my code and added some tests. Locally it seems fine, I can't see what's wrong with the "Build phase" (I've never used Google Cloud Build)

[oddcoder]

The google cloud thing is unrelated, I am in the middle of exams, will finish my exams and check, thanks in advance.

[zxgio]

No problem, thanks!