automatic version number stuff

This adds a script increment_version.sh that does the required shuffling
of changes.h and the other .h for specific versions. The layout of the
files changed a bit so that automation is easy.
version info scripts

Introduced a ./VERSION file, output version when you start ASPECT,
scripts to update version info (this updates the two places above and
the manual).
update task list
Merge pull request #91 from tjhei/version_stuff

Automatic versioning, change layout of changes.h files