Thread lines are too thick #20

Compare original shiviz:

and shiviz++:

Lines in shiviz++ are too thick, drawing user's attention to them unnecessarily.

[Issue created by bestchai: 2016-08-04]
[Last updated on bitbucket: 2016-08-09]

[Comment created by harjeetlalh: 2016-08-09]
Fixes issue #10.

→ <>

[Comment created by harjeetlalh: 2016-08-09]
Made edge stroke-width set to 1. Addresses issue #10

→ <<cset 8a5e684>>