MAINT: defer the import of shutil

[cgohlke]

numpy/lib/_datasource.py is going through the hoops deferring the import of lzma and bz2 until needed:

numpy/numpy/lib/_datasource.py

Lines 70 to 72 in d5b6b41

	# Using a class instead of a module-level dictionary
	# to reduce the initial 'import numpy' overhead by
	# deferring the import of lzma, bz2 and gzip until needed

However the lzma and bz2 modules were already loaded during import shutil earlier:

https://github.com/python/cpython/blob/49926cf2bcc8b44d9b8f148d81979ada191dd9d5/Lib/shutil.py#L21-L33

Also deferring the import of shutil reduces the initial numpy import time by almost 5% on my system.

[charris]

Thanks @cgohlke .