Improve theme Less file

[Igor Santos]

The main theme-konato.less file should look like a real Less, production-grade file:

• add scopes and includes - probably using a CSS>LESS transpiler would do
• additional variables should be defined for the other colours
• autoprefixer should be used instead of those ugly repeated prefixes
• sections should be separated into files
• theme-basic and theme-konato should be merged together into those files