Block header parsing tool

A python based tool that can interact with GNU Radio block headers written in C++, to automatically parse them and extract information about them such as which getters/setters they have, their I/O signatures, factory signatures, etc. An abstract representation of the block can be created by analyzing the header code using this tool, which would be in the form of a tree, thus making the code readable in a hierarchical fashion. Then, the abstract representation will be parsed for any further use such as creating YAML files for the GRC. GRModtool can be extended with the parsing tool as one of its utilities.