Merge pull request #193 from apiaryio/zdne/regression-fixes

Some regression issues fixes
test for resource performance added
Merge pull request #179 from alikh31/alikh31/refactor

Adding test file in order to measure Resource and Payload parser's performance
Report ignored list item nodes. Fixes #163. Fixes #189.

There was a problem that any and all markdown nodes not handled at least by the `processNestedSection()` or
`isUnexpectedNode()` were silently ignored. This is because of the behavior of the "list adapter" where advancing
to a next node causes ignoring the rest of list item's nodes. This commit changes the behavior in a way that
every node (of a list item section) is treaded as unexpected if not handled by the `processNestedSection()`.
Treat subsequent nested sections as unexpected. Fixes #188.

Unexpected blocks that are recognized by subsequent nested parser should but aren't
immediate children of the actual section should be treated as unexpected sections in the
context of the actual parser. Therefore they will be handled as unexpected block by the actual
parser without giving back control to parents. Therefore the parser can recover from encountering
an alien block and continue to parse in the actual context.