Develop time unit condition

See merge request !176

Update package to 2.2.0

See merge request !174

Change function chunk_indices() to get_chunk_indices() because chunk_indices is an item in some functions

Initialize big.matrix

See merge request !172

Create transform_crop_domain beforehand

See merge request !173

Fix typo and conditional statement for warnings

See merge request !171

marge along the dimension that has different length among files

See merge request !169

fix function creating shared object names

See merge request !167

Start() can correctly merge files along the dimension that has different length each file, without additional NAs.

Fix for the condition statement for sri chunking (transform + chunk)

See merge request !158