Load files in presentation compiler using getSourceFile

This allows files to be loaded using the encoding specified
in compiler options, rather than the system default
Make the integration test run in Windows

- sbt invocation
- use OS-dependent path names
- ensure Unix line endings in test source files
Merge pull request #533 from edani/encoding

Fix two Windows-related issues
Properly highlight setter operators taking into account the _= suffix.
Merge pull request #534 from marcsaegesser/HighlightSetterOpr

Properly highlight setter operators taking into account the _= suffix.
WIP start rearranging initialisation
WIP refactoring startup and init behaviour