a little addition to INSTALL

Hi,

I think we need to add this to INSTALL file after setting
environmnet variable TZ.

'If you compile Postgres with --enable-locale option
set locale environment to C (or unset all LC_* variables)
before starting postmaster.'

Several regression tests could failed if user's locale collation
scheme is different from that of standard C locale.

For example select_implicit and select_having failed on my
Linux machine when I start postmaster and use koi8-r locale
and passed fine if I unset all locale variables.
I don't know why collation scheme of my locale affects to english
characters ? but this could be a source of confusion for people.

results/select_implicit.out:
c |count
--------+-----
AAAA | 2
BBBB | 2
bbbb | 1 ?????
CCCC | 2
cccc | 2
XXXX | 1

expected/select_implicit.out:
c |count
--------+-----
AAAA | 2
BBBB | 2
CCCC | 2
XXXX | 1
bbbb | 1
cccc | 2

I think my locale is broken in this respect.

_____________________________________________________________
Oleg Bartunov, sci.researcher, hostmaster of AstroNet,
Sternberg Astronomical Institute, Moscow University (Russia)
Internet: oleg@sai.msu.su, http://www.sai.msu.su/~megera/
phone: +007(095)939-16-83, +007(095)939-23-83