Don’t lose warnings when building incrementally.

The builder clears all problem markers in a  given project, but not
all warnings will be reported in an incremental compiler run. For example,
the change might not require recompilation of a file that contains deprecation
warnings. In this case we’ll add markers based on the Analysis object supplied by Sbt.


See https://github.com/sbt/sbt/issues/1372

Fixed #1002148
Cleaned up EclipseSbtBuildManager.

* removed the indirection from SbtReporter to BuildReporter, which was a
  leftover from the refined build manager. No need to route through a compiler-based
  reporter anymore (and mapping back and forth between positions and severities)
* reorganized the file to start with fields and public methods
* moved all file operations to use IFile instead of compiler-based AbstractFile
Remove the build manager choice, since the refined build manager is long gone.
Additional test for builder, making sure we leave no stray error markers after undo.
Reinstate length for build error markers.

The Scala compiler uses offset positions, so errors are reported at
the starting position. We derive a length based on the identifier
at the given position, so that error markers have a non-zero length,
and look better in the UI.
Report remaining work based on the current and total work units.

The previous code was the original one, with no justification for
using `lastTotal` instead of the actual current work unit. Changed to
what seems more logical.
Keep track of what files have been compiled

The previous heuristic that a file with error markers means it was compiled
didn’t work very well. We could have a file that has no error markers but
it *was* compiled, in which case we’d add outdated error or warning markers.
Merge pull request #754 from dragos/issue/deprecation-warnings

Sbt builder fix and refactor
Add functionality to auto enable new wizard elements

Fixes #1002191
Trigger auto activation of new wizard entries only once
Add constants for Scala file creators to `ScalaPlugin`
Apply reviewer comments

- Move `RichWorkbench` to `EclipseUtils`
- Remove early info logging, because it is not very useful and maybe
  even problematic due to possible deadlocks with stdout redirecting
Updates to scala 2.11.3-SNAPSHOT
Merge pull request #755 from sschaef/t1002191-enable-new-wizard-elements

T1002191 enable new wizard elements
Fix NPE in `AllMethodsTraverserImpl`

Fixes #1002217
Change ICodeAssist to ITypeRoot in ScalaSourceViewerConfiguration

There is no advantage in working directly with ICodeAssist, therefore
this reference is removed.
Move `ScalaHover` to subpackage
Add Scala hover font configuration

This configuration is shown in

    Preferences > General > Appearance > Colors and Fonts
Add HTML aware hover

This adds a hover that can show HTML and therefore arbitrary formatted
text. It reads the config values an user specifies in the preferences and
renders the HTML accordingly. Further configuration can be done with a
new CSS file which is read by this hover.

Fixes #1001667
Add HTML creator to "show selection as type" component