[xupdate] add new ini parms "force_languages" (#53)

ini format
<pre>
[ItemKey]                ; Probably it will be the same as that of target_key, and is good.
dirname = "dirname"      ; module directory name (string)
target_key = "UniqKey"   ; Unique key (string)
target_type = "X2Module" ; TrustMudule , X2Module or Theme (string)
version = 1.00           ; Version numbar (float)
detailed_version = ""    ; Detailed version (string) [optional]
replicatable= false      ; Can replicate (bool)
addon_url = "http://"    ; Archive URL ( %s replaces target_key ) (string)
detail_url = "http://"   ; Detail page URL [optional] (string)
changes_url = "http://"  ; Recent changes page URL [optional] (string)
license = "GPL"          ; Contents license (string)
required = "normal"      ; required , recommend or normal (string)
description = ""         ; Contents description
screen_shot = "http://"  ; Screen shot URL (Theme only) [optional] (string)
tag = ""                 ; Tags of this item. Separate each tag with a space. [optional] (string)
force_languages = ""     ; Force upload language directory with `Used language only`. [optional] (string comma delimited)
no_update[] = ""         ; Do copy only installing [optional] (string)
no_overwrite[] = ""      ; Do copy only file not exists [optional] (string)
writable_dir[] = ""      ; Directory permission sets writable [optional] (string)
writable_file[] = ""     ; File permission sets writable [optional] (string)
delete_dir[] = ""        ; Directory which becomes unnecessary and it deletes [optional] (string)
delete_file[] = ""       ; File which becomes unnecessary and it deletes [optional] (string)
</pre>
[xupdate] fix warning error with md5_file()

アップロード対象ファイルへの読み込み権限が PHP にない場合に md5_file() でのチェックが warning error
になるので、その対策。
[xupdate] version 0.63
Merge branch 'xupdate' into 2.3