added variance passing with signal inav and isig views
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Test: lower the precision of the match
DOC as_spectrum(0)
DOC: SEM vs TEM
DOC: making example work for add_lines
DOC: typos
DOC: metadata update
BUGFIX: dot missing
BUGFIX: infinite loop if more elements than lines
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Test: add test for the bug
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Test: some more test
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Merge branch 'master' of https://github.com/hyperspy/hyperspy into signal_variance_inav

Conflicts:
	hyperspy/signal.py
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fixed to pass varience as required with new metadata structure
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