ActionDB 0.2.0

User visible changes:

• support JSON pattern files
• nicer and more precise error messages

Internal changes:

• Matcher becomes a trait and ParserTrie implements it
• the pattern reading and trie building code is extracted into a Builder struct
• Builder is able to populate any Matcher instance from any type which implements the PatternSource trait
  • BuildResult = Result<Pattern, BuildError>
  • BuildError contains all possible Error types (IO, pattern parse errors, etc.)
  • PatternSource is automatically implemented for every type which implements Iterator<Item=BuildResult>
  • this makes possible to generalize the Matcher building logic:
  • BuildResults are being read from a PatternSource and if they are Ok() then they are added to the Matcher
  • in case of an Err() value the building process stops and the error is returned
• Factory is introduced to create Matcher instances from files (JSON and plain pattern files)
  • Factory::form_file() is file extension agnostic and creates a Matcher instance from the given file
• the big modules are split into smaller submodules
• allow . character in Parser names
• the JSON files can contain test messages. They are tested when their pattern is added to the Matcher.
• Coveralls.io checks every modifications
• new unit tests are added