Added test for prompt support in Shell lexer
Added prompt support in Shell lexer
Added test to not confuse prompt and variable in Shell lexer
Force prompt to have at least one space after the dollar sign in Shell lexer (to avoid confusion between a prompt and a variable)
Added CSS3 attributes to CSS Lexer
Fixed a bug in detecting comments in Shell Lexer
Added support for different types of prompts ($, >, #, %) in Shell Lexer
Merge branch 'add-prompt-support-to-shell-lexer'