Call it "Git User Manual" and remove reference to very old Git version
Use correct asciidoc title level

Removes "Part I" while there is no "Part II"
Remove "Notes and todo" section
Fix typos and suboptimal wording
Improve clarifications and consistency in "Manipulating branches"
Use current "detached HEAD" message
Simplify "How to make a commit"
Improve description in "How to merge"
Simplify "Getting updates with git pull"
Remove obscure reference from "Examples"
Use "git merge" instead of "git pull ."
Use current output for "git repack"
"git prune" is safe nowadays; isn't it?
Remove irrelevant reference
Fix description in "Merge multiple trees"; remove unnecessary quoting
Remove unnecessary historical note
XXX Disable reconfiguration; create and ignore .mobi
Remove outdated/irrelevant entries from glossary-content.txt
Improve description of SHA1 related topics in glossary-content.txt
Remove definition of refspec and pathspec from glossary-content.txt