Set version to 2.0.2
test rrdValues for similar len to expected values

rather than just being non-empty
Making sure that value is pickable
moving value eval at a later step
Fixing typo
Don't send empty params ever.

Hub will now at least send 'targets' and 'expression' when things are wrong.
Collection method now will allow some missing things from the params dict.
Since we are adding values twice in rrdValues (once with targetDatapoint key and once with (targetDatasource, targetDatapoint) as key) we need to make sure we are measuring it right.
values of 0 are needed
Update docs for 2.0.2
Merge branch 'hotfix/2.0.2'