Update to latest version of https://github.com/smarr/SOM

- corresponds to smarr/SOM@2eb0115a3f6e2972e5bc48a610233011800fa30e
- not the complete update yet
- fixed parser to be able to parse larger numbers
- added reflective primitives such as #perform: and #instVarAt:
- fixed modulo operation to conform to current test case (slightly different semantics from Java)

Signed-off-by: Stefan Marr <git@stefan-marr.de>
Removed old comment, tests actually work nicely

Signed-off-by: Stefan Marr <git@stefan-marr.de>