encoding: avoid cyclic dependency around "parsers" in pure Python build
80f2b63dd83a brought "asciilower" and "import parsers" into
"encoding.py".
This works fine with "parsers" module in C implementation, but doesn't
with one in pure Python implementation, because the latter causes
cyclic dependency below and aborting execution:
util => i18n => encoding => parsers => util
This patch delays importing "parsers" module until it is really
needed, to avoid cyclic dependency around "parsers" in pure Python
build.
#require execbit
$ hg init repo
$ cd repo
$ echo foo > foo
$ chmod 644 foo
$ hg ci -qAm '644'
$ chmod 755 foo
$ hg ci -qAm '755'
reverting to rev 0
$ hg revert -a -r 0
reverting foo
$ hg st
M foo
$ hg diff --git
diff --git a/foo b/foo
old mode 100755
new mode 100644
$ cd ..