use shorter sharemem filename to avoid #200 / #203

[PaulHancock]

Seemingly simple fix to avoid issues #200 and #203 -> use shorter filenames for the shared memory.

[PaulHancock]

Suggestions:

• [x] Current filename ends with a '-' which isn't pretty and might cause errors down the road.

• [x] Could consider making a check for the os version and only shortening the filename if 'darwin' or 'osx is found.