Modify the spec of Lexer to deal with Regexp
Modify the spec of Lexer to deal with Regexp

Lexer is now able to deal with Regexp by scanning literals that begin
with a '/'.

The concept of mode has also been added in order to know if the Lexer is
scanning a String, a Regexp or just a statement.

Plus, the way unescaped characters are scanned has also changed.

Note: Anyway, refactoring is needed somehow.

ludokng/puppetshow,ludokng/puppetshow