Recognise *.dyalog as APL sources
Add sample .dyalog file for file type APL

Taken from
https://github.com/Gianfrancoalongi/APLUnit/blob/master/UT.dyalog
Merge pull request #1632 from ngn/master

Recognise *.dyalog as APL sources
Add FORTRAN samples.
Add Forth extensions .f and .for; add heuristics for Forth and FORTRAN.