Added a test case for resolving references.
Added HaskellResolveTest to the main HaskellTestCase.
Refactored parsing of imports, added support for explicit and hiding names.
Completion should take into account explicit and hiding imports.
Updated reference completion to parse and display module name instead of file name.
Updated highlighting of unit () to not apply in imports.
Updated unit () in type signature to highlight as a constructor.
Updated resolving var references to look up correct module.
Updated multi-resolve to display module names.
Updated resolve reference to look in local file if not qualified.
Fixed disabled line marker provider; refactored IElementType checks.
Optimized finding definition nodes to search for correct element type.
Implemented basic reference resolve for data and newtype constructors.
Bumped version to 0.3-beta.10
Add code style panel for Haskell, with indentation settings editor