Newbie: installation of stable snapshot

[Torfinn Ottesen]

OS: Ubuntu 6.06 LTS
I downloaded and installed the hourly snapshot of the latest version,
stable branch. I did the system wide install: '$ sudo python setup.py
install ' followed by ' $ hg debuginstall' all OK.

Two questions regarding the installation:
Q1. The documentation, man pages was not installed so I:
'cd doc', less README and Makefile and a 'sudo make install'
 --- but why did did not the 'python setup.py install' do this?
I am also curios as to why this is not a './configure; make; make
install' as "normal" (perhaps mention this in the README)? 

Checking the location of the installed program and the manual 
pages I find that the program are installed at '/usr/bin' whereas
the manual pages are installed in '/usr/local/share/man':
$ ls -1    /usr/bin/hg*                    \
         /usr/local/bin/hg*              \
         /usr/share/man/*/hg*[0-9]       \
         /usr/local/share/man/*/hg*[0-9]
ls: /usr/local/bin/hg*: No such file or directory
ls: /usr/share/man/*/hg*[0-9]: No such file or directory
/usr/bin/hg
/usr/bin/hgmerge
/usr/local/share/man/man1/hg.1
/usr/local/share/man/man1/hgmerge.1
/usr/local/share/man/man5/hgignore.5
/usr/local/share/man/man5/hgrc.5

So my second question:
Q2: In Makefile it says PREFIX=/usr/local. I have tried
reading my way through Makefile and setup.py to understand
why the programs ends up in '/usr/bin', why?
$ pwd
~/src/mercurial/mercurial-c620376b8fd6
$ head Makefile
PREFIX=/usr/local
export PREFIX
PYTHON=python

I am sorry if my understanding is completely flawed, I have no
excuse but being a complete newbie in both version control and
installing from source.  

Regards
TO