Removing deprecated note from obspy.core.trace
doc: Fix external references in obspy.signal.
doc: Make signal.tf_misfit a bit more consistent.
doc: Remove unnecessary braces in citation.
doc: Fix some more rendering bugs in obspy.station.
doc: Use 'str' for types.
doc: Move a couple more 'optional' to the types.
Merge branch 'master' into doc-fix
doc: Americanized behavior.
doc: Move possible values from types to descriptions.
doc: Change some list formatting.
doc: Fix a few minor grammatical errors.

These are just some random things I found along the way; not a full
review.