load_cube now uses merge_cube
Merge pull request #1026 from niallrobinson/load_cube_merge_report

load_cube now uses merge_cube
DOC: Resolves feedback on the statistics docs.
Merge pull request #1029 from dkillick/back_out_concat

Backed out unify_time_units call in concatenate
Merge pull request #1018 from pelson/further_links_in_userguide

DOC: Resolves feedback on the statistics docs.
Added a custom aggregator example.
Merge pull request #1030 from pp-mo/custom_agg_eg

Added a custom aggregator example.
Added support and test for mixed-case calendar strings
Updated copyright notice dates to include 2014
Forced calendar string added to unit to be lowercase
Corrected test failure
Improved calendar checking logic. Added associated test
Convert method references local calendar variables