Re: git-gui: i18n introductory document (2nd draft)

My thanks go to Nana, VMiklos, Christian and Brett for their feedbacks to the draft.

It quickly gets cumbersome, both for myself and reviewers, to go back and forth sending the whole of Nth draft every time on the mailing list. At the same time, I can not really afford to be in the translation business myself, so I'd like to let this document go in the best shape I could make, and have people more competent around gettext than me to take it over.

I've updated the document somewhat and pushed it out to the mob branch. The issues I addressed:

 * "Running without installing does not work with ./git-gui, but
   with ./git-gui.sh" (Nana).

 * After the initial cloning, resulting local directory is
   git-gui-i18n, not git-gui-i18n.git (VMiklos).

 * "Please install them" (Christian).  I meant by "them", git,
   gettext and any one of po editors.  I reworded the example
   enumeration of available po editors to make it clear the
   translator needs only one.

 * "Parameter permutation needs $ sign quoted" (Brett).

 * "Message marked with '# ,fuzzy' are not used -- remove the
   fuzzy marker when you are done" (Christian).

I did not address the following issues, not because I did not agree with the comments, but because I felt Christian is more qualified to do these kinds of things.

 * "Parameter permutation" should be in a separate "Advanced
   translation" section (Christian). 

 * "po/git-gui.pot" should be generated by translators any time,
   and other workflow improvements regarding merging of the po
   files (Christian).