WIP: building smaller thesauri on demand
Fixed failing unit tests from yesterday
Pipeline compatible with both Vectors and Thesaurus

 - A single method get_nearest_neighbours() is used for both
 - options that differ between the two (allow_lexical_overla is applied
  at different times) made consistent
 - shelving is optional as events files are much smaller than
  neighbours ones and thus there's no need for that
Cosmetic
Removed confusing and useless entry_types_to_load param

This only made sense when we were loading huge thesaurus. Vectors files
are smaller, so the performance gain isn't worth the effort (had to be
clever about feature selection)
Cosmetic
Picklable Delayed
Generating conf files for technion datasets
Merge branch 'online-thesauri' into dev
Parameters now passed into Vectors constructor by from_shelf_readonly

Previously allow_lexical_overlap was effectively ignored when calling
from_shelf, resulting in different neighbours when using the optional
shelving step