fix: avoid spurious messages in debug output (unless debugging mpr stuff)

from spielwiese
fix: for PLURAL: len(p) != len(m*p)

from spielwiese
fix: error check for sleftv::Eval() (id not found?)
Avoid empty wildcard pattern in Makefile
Replaced some system calls by safely wrapped versions
Special handling of nanosleep
Systematically checking for missing wrapped interupable system calls
Wrapping sscanf in libparse.l
Wrapping EINTR-affected system calls in old dyn_modules (possibly dead code and untested)
Wrapping system calls in omalloc
Merge pull request #305 from alexanderdreyer/master-signals

Interrupt-safe system calls
chg: removed SI_THREADS (unused)
fix: order of include files (mod2.h before all non-system stuff)
fix: porting(pselect), porting/unused (sem_timedwait,dup3)
fix: more porting stuff (order of includes)
fix: porting/unsed(waitid)
unify with spielwiese
fix: singular.doc does not used uname.texi