moved header text to eden_headers.py, included parameter codes in
download header
reorganized header generation
Merge pull request #2 from ayan-usgs/master

modifications to download headers
Merge remote-tracking branch 'upstream/master'

Conflicts:
	dj_eden_app/nwis_rdb.py
	dj_eden_app/views/data_views.py
Tidy after merge.
Let file writer handle line endings in rdb output.