[Fix #471] Use source-inplace for less
Fix some docstrings
Use while loop over -any?
Drop redundant flycheck-sort-errors
Make level required for flycheck-has-errors-p
Add functions to check maximum error level
Streamline :next-checkers

Instead of mucking about with custom predicate symbols, just specify the
maximum permissible error level.
Merge pull request #472 from flycheck/refactor-next-checker

Streamline :next-checker predicates
Bump version [#472]

Announce a breaking API change
Fix doc building [#472]

Regression from 1f9c17f
Update changelog and Texinfo manual