add BESA .elp support to read_montage

Direct translation of EEGLAB routines for reading spherical BESA .elp channel location files.
Not to be confused with polhemus .elp files.
Possibly need smarter way of handling header files; the only example I know has 1 header line, but there may be other formats.
add dots

floats instead of integers
update nosiest to include .elp
Update layout.py

fix pep8
pep8
update what's new + adding name to file