Second release

Updates:

• Bugfix in BFS and now it's multithreaded, in case the user had too many start nodes and the neighborhood size is big
• Connected components now outputs n biggest component instead of all of them, also user can choose to sort the components based on seq size or node size
• other minor bug fixes

First release

GFASubgraph extracts a subgraph of user-defined size around a node. It can also separate connected components into individual GFA files. First release, might have some bugs