Add way to merge consecutive collections

[patrickdevivo]

This library is primarily used for parsing comments out of source code. One feature that would be nice to have is a way of merging consecutive comments that only have whitespace characters between them. For instance,

    // This is a code comment
    // which spans two lines

The above snippet would be parsed as two separate comments (two collections). A feature of this library that would allow them to be merged at parse time would be great to have so that consecutive line comments could be treated as single units