Issue #239: Fix all Smalltak/X source files to be in unicode (UTF8 without BOM) and prefixed by "{ Encoding: utf8 }" when any unicode character is present
- All source *.st files are now Unicode UTF8 without BOM
Files are in two groups (fileOut works this way in Smalltalk/X):
- containing a unicode character have "{ Encoding: utf8 }" at the header
- ASCII only are without the header