Add a shell script alternative to run-with-lockfile
Add a shell script alternative to run-with-lockfile

It is useful to have something like this in commonlib,
since several mySociety sites use run-with-lockfile,
but that helper is only in the CVS module 'mysociety'.
Additionally, it is convenient not to have to
compile the binary, and this version should be NFS-safe.

MorusAB/commonlib-fmg,MorusAB/commonlib-fmg,MorusAB/commonlib-fmg,MorusAB/commonlib-fmg,MorusAB/commonlib-fmg,MorusAB/commonlib-fmg,MorusAB/commonlib-fmg,MorusAB/commonlib-fmg