ERT-382: Added ens_mask argument to analysis->init_update() method.
ERT-382: Added matrix_resize() fastpath when the new size equals the current size.
ERT-382: Added new function matrix_columns_equal()
ERT-382: Added assert that the total size of the ens_mask is correct.
ERT-382: Added functions rml_enkf_common_store_state() and rml_enkf_common_recover_state().
ERT-382: Changed the rml modules to use store and recover state functions which should handle changing number of realisations.
ERT-382: Fixed bug in size_assert().
ERT-382: Keeping track of initial prior; and selecting and active prior for each step.
Merge pull request #379 from joakim-hove/ERT-382-size-mismatch

Ert 382 size mismatch