Use `Import-Package` instead of `Require-Bundle` for org.eclipse.core.runtime.

This should allow Luna installs without conflicts due to “double vision” of
the `javax.bind.ws` package. This workaround was suggested in this Eclipse ticket.

https://bugs.eclipse.org/bugs/show_bug.cgi?id=430458
Update pref store reference in `ScalaSourceViewerConfiguration`
Update pref store references in scanner classes

There was no need to use multiple pref stores, only one is used now.
Replace references to Java partitions with references to Scala partitions

This shouldn't introduce any functional changes beside from the point
that everything related to partitioning (syntax highlighting, auto
edits) have a chance to not work anymore.

Some new Scala partitions are added, they replace partitions located in
`IJavaPartitions` and `IDocument`.

Because this is a no compile-time-save change, it could be that some
references are forgotten, but hopefully my grep-foo caught them all.
Enable Scala partitioning on all Scala files

After all referenes to Java partitions were removed, syntax highlighting
didn't work anymore because the `IDocumentSetupParticipant`, that
intrnally uses Java partitions was inherited from the Java plugin - a
problem which is solved by this commit.
Add new Scala partition to constructor call of `JavaHeuristicScanner`

The previously called constructor forwards to another constructor by
passing Java partition references, which obviously are not the right ones.
Merge pull request #742 from sschaef/remove-java-partitions

Remove java partitions
Revert "Merge pull request #742 from sschaef/remove-java-partitions"

This reverts commit e69c738c68034deb8a9e64f667240ac4f0229609, reversing
changes made to f9098ee6cb35a6f5dcd3dc917205d359c1fb1d8d.
Merge pull request #753 from huitseeker/revert-742

Revert "Merge pull request #742 from sschaef/remove-java-partitions"
Merge pull request #751 from dragos/issue/resolution-order-luna

Use `Import-Package` instead of `Require-Bundle` for org.eclipse.core.runtime
Treat projects in subfolders correctly in `NewFileWizard`

Normally a project is located in the root of the workspace, which would
lead to a physical location like '/workspace/project/file'. But it is
totally valid to have a file in a physical location like
'/worskpace/subfolder/project/file'. It is even possible to have source
folders that are linked resources and can therefore be located anywhere
on the file system. In these cases the wizard did not work correctly.

Internally the wizard was based on `IPath` types which was a problem
because they couldn't handle linked resources perfectly well. In case a
linked source folder points to another folder in the workspace, an
`IPath` object did always point to the real file on the file system. If
the path would have pointed to the symlink there would have been no way
to determine its real location.

To overcome this limitation the `IPath` references were replaced by
`IFile`, which abstracts over workspace files and therefore can
correctly recognize symlinks.

Fixes #1002185
Select project explorer element after wizard created new file

Fixes #1002188
Apply reviewer comments

- NewFileWizard.pathOfCreatedFile is renamed to
  NewFileWizard.createdFile
- FileCreator.createFilePath is renamed to FileCreator.create
- FileUitls.createFile uses IResource API instead of Java file API
Merge pull request #748 from sschaef/t1002185-subfolder-support-for-wizards

Treat projects in subfolders correctly in `NewFileWizard`
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.