Merge pull request #47 from santosh/master

Use more consistent markdown hyperlinking for the README file.

The old way could, potentially, bit us in the future. The new way may be more
cumbersome, but it is safer.
First try to use BeautifulSoup 4, then try BeautifulSoup 3.

BeautifulSoup 4 is potentially faster (and, if the placebo effect isn't
operating here, it does work faster on my 400MHz ARM-based NAS with 128MB of
memory).

To get the most benefit from BeautifulSoup 4, the user should install
python-lxml, which consists of Pythonic bindings to the libxml2 and libxslt
libraries (written in C).
Revert "First try to use BeautifulSoup 4, then try BeautifulSoup 3."

Although I can't reproduce it, some people seem to have found problems with
the use of BeautifulSoup 4 by default. This hopefully fixes issue #48.

This reverts commit f79dddeece30d696d9ec2ea6f6fb5c05eea9c397.