[PATCH 00 of 19 STABLE] largefiles: fix bugs of "hg status"

[FUJIWARA Katsunori]

this patch series fixes bugs of "hg status" with largefiles extension.

many of patches in this series are refactoring ones as preparation for
bugfix in #7, #10, #12, #14, #16, #18, and #19.


BTW, in my plan, 'match.convert()' added by patch #2 in this series
will be also applied on other match object modifications in current
implementation of largefiles extension for refactoring of them.