Allow to query non-existant sections

[an-ky]

Sometimes it is convenient to query a library for a specific section and expect an empty result if the section does not exists. This was not possible because library_info ASSERTed the section adresses thus crashing the Application if a section was not found. Fixed this by checking section begin and end and returning an emtpy vector of string if the section was not found.

It seems only affect pe_info.hpp, the other implementations seem to allow empty sections (or handle them differently altogether)

[coveralls]

Coverage remained the same at 93.122% when pulling c412ace49d876392cf7c36167cc6b2b6504af5a3 on an-ky:develop into b09c0b856779c1e6dae74d2ef042fac3b6bfb51d on apolukhin:develop.

[an-ky]

Ohh my bad, first of all I overlooked that library_info.sections() can be used to check for existence of a specific section. Second I missed to add tests for the case. Do you think this is a valid change of the library_info? Then I will extent the tests, of course.

[apolukhin]

Seems to be a good addition. Please add tests and I'll merge your pull request.

[coveralls]

Coverage remained the same at 93.122% when pulling 54bdb7cc745e1802c6b5ca1989e06edf35e4cda7 on an-ky:develop into b09c0b856779c1e6dae74d2ef042fac3b6bfb51d on apolukhin:develop.

[an-ky]

Is this test appropriate? Sorry for spamming here, I'm overwhelmed by the grade git hub is automated. Awesome on one hand, confusing if one is not used to it.

Regards

[apolukhin]

Thanks! Everything is good!