remove some register keywords; let the compiler do its work.
workaround bashism
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.
Spelling.
Add "prove", to run individual test.