* Added info on focus/ignore/show/hide to legend on graphs

* Made separate function for formatting filters in legend

By default hide entries in the comment field that starts with #, and
add a "comments" command to show all comments.

When reconciling samples, cleanup file paths to allow functions to be
combined if their source filenames match after cleanup (eg "src.cpp" and
"./src.cpp").

Also clean up existing uses of filepath to avoid passing empty strings
to it: filepath.Base("") returns "."

Also update the build instructions to use go get