Reorganize files

Reorganizes the documents to be more in line with my planned teaching for fall
2013; instead of having separate 'point estimation' and 'inference' documents,
I have 'finite sample' and 'asymptotics'
Update README to reflect file reorganization
Add shortcuts to common preamble

This commit adds a lot of unicode shortcuts to the common preamble,
other commits will make these changes in the LaTeX documents.
Convert asymptotics doc to unicode

A hopefully comprehensive conversion of LaTeX code to unicode
characters wherever possible in the asymptotics files.  This change
should make the source code easier to read.
Convert LaTeX characters to unicode in linear regression doc

Another (hopefully comprehensive) attempt to improve the
source code readability by converting LaTeX to unicode
wherever possible.
Convert LaTeX to unicode in finitesample docs

A last readability improvement by converting LaTeX characters
to unicode.
Convert LaTeX to unicode in probability document

One more attempt to improve source-code readability by converting
LaTeX characters to unicode.
Reduce TOC and section numbering depth

Having subsections show up in the table of contents is unnecessary; this patch
removes them.
Change page numbering for front and back matter

* Removes the ToC and the bibliography from the ToC
* Changes page numbering for ToC to lower-case roman
Both of these changes are being made because the ToC are going to
effectively define the API (as far as semantic versioning goes), so I don't
want the ToC and bibliography locked in as unchangeable.
Put references back in ToC

The list of references should be easy to find, so it's back in the ToC.  I've
also decided not to support page numbers as part of the API, since they are
meaningless if I decide to make html files from these documents too.
Roll-back page numbering change

Since I've decided that the page numbers should not be part of the API, it
makes sense to just have one numbering scheme for each pdf and start the first
page at '1'.
Update to version 0.2.1

* Converts LaTeX characters to Unicode where possible.
* Reduces TOC depth