Refactoring in api.py
Remove different api versions feature.
Remove API version argument from flask routes.
Tweak core cmar download to use boto for S3 files.
Remove unused diff files from cache.
Tweak frontend api to upload to S3 files received in POST form.
Bugfixes - change hash args in frontend and client.
Cache save() set contents from file pointers instead of strings.
Mark mar hashes as their urls for S3 complete mars.
Bugfix in identifying the S3 mar_urls.
Remove unused variables.
Bugfix in core.py
Move lines to gain little efficiency.
Change POST request size limit to 100 Mb.
Change client script called in backgroun compat test.
Move mbsdiff_hook.sh file into funsize/backend.
Client dir cleanup as following funsizer pypi package.
Cache cmars anyway.
Tick a todo, complete README with client side info.
Add some known bugs in the TODO file.