minor stuff
extension method on string to allow a multiple contain search on the string
added symbols
OpeningCurlyBracket
ClosingCurlyBracket
OpeningSquareBracket
ClosingSquareBracket
Add EmptySymbol as a wildcard
RemoveAfter<T> added
previous RemoveAfter renamed to TakeUntil
Added new RemoveAfter impl.
Some tests
RemoveTokensAfter and RemoveTokensFrom methods added to allow callers change the token collection of the lineInfo instance
Minor fixes (update string representation when tokens collection is modified)
Added method TokenizeBracketExpression to tokenize lines with [ ... ] operations
previous commits were to support this