Better emi xml reader and fix a bug that raised an exception when loading image stacks
Merge branch 'ENH_dm4' into ENH_FEI_reader

Conflicts:
	hyperspy/tests/signal/test_1D_tools.py
Small corrections to the docs
Add mapping to some parameters
Merge branch 'master' into ENH_FEI_reader
Merge pull request #95 from francisco-dlp/ENH_FEI_reader

Enh fei reader