Code cleanup in layout
Update rust version in README
Fix and refactor block positioning
Rename layout_block_content to layout_block_children
Style fix
Negative width is illegal
Update comment on layout_block_children
Minor comment and formatting changes
Fix deprecation warnings
push_char was deprecated, renamed to push
Update range pattern syntax

Fixes #3.
Merge pull request #1 from mbrubeck/master

Trying out pull request.  Bring my robinson code up to date.