Fix parsing of signatures

It remains to discuss whether idents followed by keywords
are truncated or not:

 "StringDEF" = "String" "DEF" | "StringDEF" ?
Prepare int2Str

Signed-off-by: Christoph Höger <christoph.hoeger@tu-berlin.de>
Add int to string conversion

Signed-off-by: Christoph Höger <christoph.hoeger@tu-berlin.de>
Merge branch 'master' of https://github.com/choeger/sl2
Add real2Str conversion

Signed-off-by: Christoph Höger <christoph.hoeger@tu-berlin.de>
Add char2Str conversion

Signed-off-by: Christoph Höger <christoph.hoeger@tu-berlin.de>
Put predefined functions where they belong

Signed-off-by: Christoph Höger <christoph.hoeger@tu-berlin.de>
Fix most stupid bug ever

Signed-off-by: Christoph Höger <christoph.hoeger@tu-berlin.de>
Sort constructors lexicographically

This allows to predict the tag

Signed-off-by: Christoph Höger <christoph.hoeger@tu-berlin.de>