Develop time unit format

See merge request !129

Revise checks for return_vars names

See merge request !132

Stop if merge_across_dims and split_multiselected_dims are both used but this file dim selector is multi-dim array

Consider different dim order when finding the largest dim length

See merge request !131

Fix the time unit attribute retrieval if the format is YYYY-M-D. Also, split_multiselected_dims is changed to FALSE if it is useless.

Consider implicit inner dim in return_vars name check

See merge request !128

Split Start() into internal functions. Part I

See merge request !125

Fix the calendar retrieving line to consider synonims.

See merge request !127

Remove incorrect check of character selector.

See merge request !126

Develop wrong name return vars

See merge request !124

If the name of return_vars is the synonmin of inner dim name, change it back to inner dim name. Unit test added.

Update version number to 2.1.0-2

See merge request !122

Force return_vars to have value when inner dim has dependency on file dim.

See merge request !121

Warning update for parameter crop in transform_params

See merge request !120

Develop time attr month unit

See merge request !119