intel-ref -- Look up identifiers in intel's instruction reference PDFs

Intent is to map this to a lookup key in Vim so pressing that key launches the
PDF reader with the instruction up on the screen. Intel made the
searching/jumping impossible by splitting the instruction set into two PDFs.

Setup:

1. Install the Skim PDF reader
2. Download Intel's two instruction manuals A-M and N-Z.
3. Place the PDFs in this directory, call them intelref_am.pdf, intelref_nz.pdf

Usage: intel-ref.py intel-ref.txt <instruction>

The included index requires the exact intel document versions with the
following MD5 checksums as it is based on page numbers:

MD5 (intelref_am.pdf) = e0587665594448f298c29a42ceff544a
MD5 (intelref_nz.pdf) = 3a42f6cda86e000a14229c450e66f49e


Rebuild/Install: 

The included Makefile will regenerate the intel-ref.txt from intelref_*.pdf, and
optionally install the files and the intel-ref script to DESTDIR. You'll need to
have the pdf2txt and xml2 packages installed.

$ DESTDIR=~/opt make install
$ ~/opt/bin/intel-ref AAA