Added git clone depth of zero to travis CI config.
Merge pull request #541 from esc24/v1.4fixed

Added git clone depth of zero to travis CI config.
MAIN: Removed all whitespace and file-end lines
Merge pull request #538 from cpelley/whitespace_rm_v2

STY: Removed all whitespace and file-end lines
1.4 changelog and what's new
Merge pull request #540 from bblay/suuup

1.4.0 changes and what's new
Bumped version to 1.4.0rc1
Restore version back to 1.4.0-dev
Merge pull request #544 from esc24/1.4.0rc1

1.4.0rc1 version number
v1.4.0
v1.4.1-dev
Merge pull request #556 from bblay/v1.4.x

Release v1.4.0
Doc tweaks for custom season categorisation
Merge pull request #558 from rhattersley/custom-season-doc-tweaks

Doc tweaks for custom season categorisation
unit doc
Hack in pure-Python PP rules
Add GRIB support and fix remaining issues/tests.
Remove obsolete methods
Remove quickplot unit label for time reference coordinates. Closes #615.

1D plots in quickplot omit the units part of the axis label when the
coordinate it represents is given as a time reference, and hence will
have been converted to an absolute date/time.
Added function to display differences between cubes that prevent compatibility.