increment flex version to 2.6.0
move flex program sources into src/ directory

The *.[chly] sources are now in the src directory. This implies a
bunch of changes in Makefile.am and friends to account for the new
location. The .gitignore files are now more local to places where various object files and generated source files occur.
mention version 2.6.0 in release news
removes extraneous files from EXTRA_DIST as automake picks them up better without mentioning them
Add tools/ directory.

Since tools/git2cl is a dependency of ChangeLog, not distributing
tools/git2cl with flex causes the "make dist" target to fail in the distributed tar ball.
list source files for translation as now being in src/
git ignore directories of the form flex-*
Add make rule to rsync latest .po files from translation project.

The rule assumes that rsync is on the path and that there is exactly
one domain listed in the DOMAIN make variable. The intent is that the
rule will work with vpath builds.
remove unused devel/ subdirectory from codebase
move m4 make variable to src/Makefile.am.

This prevents an error when building skel.c caused by the $(m4) make
variable not being defined. Particularly nasty since skel.c would
still be created, thus causing make to think skel.c was up to date.
Adjust buffer sizes on ia64.

From the debian change entry:

> Finish fixing the ia64 buffer issue. Previous commits increased
YY_READ_BUF_SIZE (where __ia64__ is defined) but left YY_BUF_SIZE
unchanged, so that didn't fix the problem in the end. In the general
case, the latter is twice the former. Therefore set it to the same
ratio in the ia64 case.

In general, this sort of architecture specific fix is not the path we
want to take, but the cleanup should be done in a more organized way
in the future and getting it working would be preferrable now.
initial default control file for shipper
mention flex 2.5.39 release in NEWS file