convert: when converting from Perforce use original local encoding by default
On Windows Perforce command line client uses default system locale to encode
output. Using 'latin_1' causes locale-specific characters to be replaced with
question marks. With this patch we will use default locale by default whilst
allowing to specify it explicity with 'convert.p4.encoding' config option.
This is a potentially breaking change for any scripts relying on output treated
as in 'latin_1' encoding.
Also because hgext.convert.convcmd overwrites detected default system locale
with UTF-8 we had to introduce an import cycle in hgext.convert.p4 to retrieve
originally detected encoding from hgext.convert.convcmd.
$ hg init repo
$ cd repo
$ touch foo
$ hg ci -Am 'add foo'
adding foo
$ hg up -C null
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
this should be stored as a delta against rev 0
$ echo foo bar baz > foo
$ hg ci -Am 'add foo again'
adding foo
created new head
$ hg debugindex foo
rev offset length ..... linkrev nodeid p1 p2 (re)
0 0 0 ..... 0 b80de5d13875 000000000000 000000000000 (re)
1 0 13 ..... 1 0376abec49b8 000000000000 000000000000 (re)
$ cd ..