From libreoffice: deprecate os2-gcc in make.cmd.
Bring in some small changes from LibreOffice:

Handle NetBSD like the other BSDs in more cases.- Thomas Klausner
Add DragonFly defines. 				- Francois Tigeot
distinguish exit due failure vs signal aborted	- Caolan McNamara
free after use					- David Tardon
dir is always copied--free unconditionally	- David Tardon
Output the "Executing shell macro" only with -vr- Tor Lillqvist
don't let our fprintf pollute errno		- Michael Meeks
workaround bashism
remove some register keywords; let the compiler do its work.
Bring some more cleanups from LibreOffice:

Fix typo (Successfull) - Stefan Knorr (astron)
later cygwins have a different locaton for process.h - Noel Power
Avoid unused variables code warnings - Martyn Russell
From libreoffice: disable double-% warning.
From libreoffice: support os2 in startup/unix/Makefile.*
From libreoffice: check fread return code.
From libreoffice: make loop-counter "register".
From libreoffice: spelling, RCS tag removal.
Create README.md
Add .gitignore
Remove obsolete test targets-9 (multi-% warning check).
Get tests permissions right.
Fix dircache test - logic was wrong.
Stop tracking autoconf-generated files.
New version will be 4.13.
Update to latest(ish) autotools.
Test "-quoted targets work.
Make autogen.sh exit immediately on fail with -e.