GitLab

Changed the public interface of Scanner to resemble an STL container.

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.

Combined the myriad ScannerExceptions and ParserExceptions to a single ParserException class that has a message and a line/column position in the file where the error occurred.

Fixed a bug in the last newline of a block folded scalar.

Specialized the overloaded [] operator for int/unsigned, and added a size() function, so that you can iterate through a sequence node like a vector.

Fixed a silly bug in the simple key pushing (queues are FIFO!).