Amend type declarations for R18
Migrate demo source files to another directory
Generalize the from_file function.

Allow the creation of graphs that have user defined vertices.
Refactor graph.erl & Add demo functions

* add_edge properly adds 1 edge to directed graphs
and 2 edges to undirected graphs
* Add demo for loading graphs from files with the
default syntax & with custom vertices
* Add demo for manually creating a graph
Update copyright years
Minor refactor BFS code & add demo
Cosmetic changes in documentation
Minor refactor in heaps & add demos
Minor changes in union find & add demos
Minor refactor in dfs & add demos
Minor cosmetic changes in dijkstra & add demo
Minor cosmetic changes in kruskal & add demo
 Minor cosmetic changes in flow & add demo
Add A* Search Algorithm & demo
handy heap
add .gitignore