Implemented new strategy for merging cflow and gprof call graphs. Assuming all CflowCall objects with no function_signature represent library calls.
Fixed nodes and edges oracles in call graph merge test cases.
Added functions for detecting disconnected components. This is still not ideal because of the need to convert the DiGraph to an undirected graph in order to get the components.
Added logic to suport parsing gprof callgraphs executed with the -z option,
Handled a couple of exceptions that happened when generating the reports with call graphs that did not contain entry points and/or exit points.
Added mechanism to store error messages while parsing call graph information. Only GprofLoader needs this for the time being. Added BaseLoader to the loaders package __init__.py file. All loader classes now inherit from BaseLoader.
Added error message support for CallGraph class.
Added error message support to merge call graph generation.
Added a -e command line argument to show the parsing errors list along with the attack surface report.