Uninformative message: Not enough blocks in datastore

[GertjanBisschop]

The gimble info module should always report on the content of the datastore and generate numeric output even in the absence of blocks, windows, .... An array without blocks has dimension 0.
The current 'not enough blocks' could imply that there 9 blocks have been made yet that for some magic reason this does not suffice. If 9 is not enough we should report. Found 9 blocks, yet cut-off for meaningful analysis is 5 (or whatever).

Code is here.
Bug reported in #138.

[GertjanBisschop]

see #135, reports same bug.