Add --version option

Change-Id: I8904a8205b10fd7f169cf40a4b6220819a3d60cd
Update README.txt with links to dependencies.

Change-Id: I65a55d44cb7677326d5f9e5bf6e858b0a4e3f60b
Add pencil repository as a submodule

Change-Id: Ib585042207ae7a421c1072a1370bc1e1c1100bf9