manpage: minor corrections

$ groff -ww -mandoc -z strace.1
strace.1:65: warning: macro `IX' not defined

* strace.1: define IX macro as empty for groff.
Change remaining '-' as minus to '\-'.
Have two word spaces after a full stop as an end of sentence.
Use extra space ('\,' or '\/') between roman and italic characters.
Based on patch by Bjarni Ingi Gislason <bjarniig@rhi.hi.is>.
This fixes Debian bug #725987.
1 file changed