Some experimentation with drawing borders around text.
Added quick TODO for border calculation.
Merge branch 'master' into draw_borders
Different experiment
Fixes to margins.
Merge branch 'master' into draw_borders

Conflicts:
	src/main/java/net/nightwhistler/htmlspanner/HtmlSpanner.java
Can now draw borders and full background colours.
Borders mostly working.
Updated version number to 0.5