GitLab

Flipped the include guard and the pragma, and don't use the pragma for early versions of gcc (< 3.4)

Fixed bug in anchors with no content. This involved refactoring the 'implicit sequence' concept (where a map and a sequence start on the same indent, but we read the sequence as more indented since the '-' is visually an indent).

Switched from loading test files to testing specific parsing constructs. The tests don't fully cover the span (eventually I'll add more, maybe), but there's a bunch there.
More to the point, the yaml-reader program doesn't do any file IO, so it doesn't require a specific working directory.

Added CMake scripts for other platforms\nFixed some bugs that gcc complained about\nFixed CR/LF vs LF bug

We were getting memory leaks (as told by the CRT detectors, which I also added), and there's really no reason (as long as we're careful) to use pointers there.