[PATCH 00 of 55 RFC c-hglib:level1] c-hglib API level 1

[Iulian Stana]

This is a draft of my work for c-hglib up to now, I am sending this to the list
for public review (even if this is not a patch for the core mercurial). I am
sure that the main developers following my work (Matt, Pierre-Yves, Idan and
others) will have important remarks on the architecture and on the style, and I
like to solicit those feedbacks.

This patchbomb will containt all mercurial commands, implement for this API. All
those commands are implement useing level 1.