[TEMP] Suppress rebuild if only version number changes

This commit takes CITATION.bib and VERSION.tex out of the prereqs
for the pdf files.  They still must be regenerated, but this way
pdfs that are otherwise unchanged are not rebuilt by make.

Conflicts:
	Makefile
[TEMP] Remove sections of FDL from table of contents
Rewrite introduction to asymptotic material

Rewrites the introductory L_p material using sentences and paragraphs.
Rewrite convergence in probability material

Revises and streamlines the convergence in probability and WLLN
material.
Rewrite almost sure convergence material

This commit cuts the computer material for almost sure convergence
and rewrites the text in paragraphs and sentences.
Start CLT section
Move almost sure convergence to probability document

Almost sure convergence plays very little role in the first year
econometrics sequence, so I think we'll just mention it (and the SLLN)
in passing towards the beginning and focus on Lp and convergence
in probability in the asymptotics document.