test-install: embed wix namespace for Python 2.6 compatibility
According to doc, the syntax is "{uri}tag".
https://docs.python.org/2.7/library/xml.etree.elementtree.html#parsing-xml-with-namespaces
Mercurial
=========
Mercurial is a fast, easy to use, distributed revision control tool
for software developers.
Basic install:
$ make # see install targets
$ make install # do a system-wide install
$ hg debuginstall # sanity-check setup
$ hg # see help
Running without installing:
$ make local # build for inplace usage
$ ./hg --version # should show the latest version
See https://mercurial-scm.org/ for detailed installation
instructions, platform-specific notes, and Mercurial user information.