Correct partitioning of octal sequences in character literals

The previous behavior was not correct because an octal sequence can
start not only with a '0' but with all signs between '0' and '7'.

Fix #1001443
Add syntax highlighting for escape sequences in character literals

Fix #1001444
Refactoring in ScalaSourceViewerConfiguration

- Grouping of code highlighting parts
- Allow iteration of components instead of managing them
  manually to reduce errors
Merge pull request #275 from sschaef/issue/partitioner-correction

Correct partitioning of octal sequences in character literals
Merge pull request #276 from sschaef/issue/escape-sequences-characters

Add syntax highlighting for escape sequences in character literals
Merge pull request #277 from sschaef/issue/sourceviewer-refactoring

Refactoring in ScalaSourceViewerConfiguration