Documentation fixes

This is NOT complete yet, but it's probably good to get out there since early review is better. I also have a couple of questions. These changes fix rendering issues, make things more consistent, etc. I've also noticed that my current docs seem a bit incomplete, and I'm not sure if I broke it myself. Admittedly, I don't know a whole lot about the combination of sphinx, autosummary, autoclass, etc.

Anyway, what this does is:
 * Consistent types:
     * `int` instead of integer, Integer, Int, etc.
     * `bool` instead of boolean, Boolean, Bool, etc.
     * `float` instead of Float
     * `dict` instead of Dictionary
     * `list of X` instead of a myriad of others
     * `<type>, optional` instead of placing Optional elsewhere (like in the description)
 * Cross-referencing fixes
 * Fix warnings about indentation and unterminated styling.
 * Spelling fixes

I do have some questions:
 * str or unicode for documented types? (String and string are used in some places, too)
 * American English or not? There's "color" all over, but then there's "behaviour" too...
 * Not sure how to fix a few remaining warnings:
     * Lots of "failed to import" instance variables from `obspy.seedlink`
     * Warnings that "obspy.core.json", "obspy.core.util", "obspy.core.util.geodetics" are not included in any toctree, though they end up in the produced HTML pages somehow?