Added support for tracking created sysmlink through strace runner.

Valid symlinks are now autocleaned.

Invalid ones are not cleaned yet. This will be rectified along with the fixes for mkdir not being cleaned.

git-svn-id: http://fabricate.googlecode.com/svn/trunk@158 7d55530a-7836-11de-8a01-315fa775be5f
StraceRunner now correctly supports mkdir operations and lists them as output files. Directory path names are hashed instead as there is no file content.

Created directories are deleted during autoclean, once all normal files have been deleted.
Directory removal is ordered so parents are removed after any children.

strace mkdir failures are detected and logged as input files rather than output files.
This handles the -p option of the mkdir command, and hopefully any other instances where the existing directories are relevent.

git-svn-id: http://fabricate.googlecode.com/svn/trunk@159 7d55530a-7836-11de-8a01-315fa775be5f
Added a set of tests sripts for the new symlink and mkdir functionality

Also a test for rename functionality and a low level test of the new md5hasher function

git-svn-id: http://fabricate.googlecode.com/svn/trunk@160 7d55530a-7836-11de-8a01-315fa775be5f
merge in latest changes to upstream