Add Boolean to result of AndOrListParser

More than one and-or list cannot be sequenced without the semicolon or
ampersand operator in-between. The and-or list parser has to return
whether there was an operator so that the sequence parser can decide if
and-or lists can be sequenced.
Fix namespace of AndOrListParserTest.cc
Add missing Keyword::keywordEsac
Make Converter::resetImpl protected

A member function has to be protected (or public) for a derived class to
override it.
Add SequenceParser abstract class
Add SequenceParserImpl class
Merge pull request #56 from magicant/feature/sequenceparser

Implementation of sequence parser