vcscommand.vim is what you are looking for. I have not used it with Git or Mercurial, but I really use it with Subversion. Check the documentation for all the commands; the display section tells you how to call them:
|<Leader>|ca VCSAdd
|<Leader>|cn VCSAnnotate
|<Leader>|cN VCSAnnotate!
|<Leader>|cc VCSCommit
|<Leader>|cD VCSDelete
|<Leader>|cd VCSDiff
|<Leader>|cg VCSGotoOriginal
|<Leader>|cG VCSGotoOriginal!
|<Leader>|ci VCSInfo
|<Leader>|cl VCSLog
|<Leader>|cL VCSLock
|<Leader>|cr VCSReview
|<Leader>|cs VCSStatus
|<Leader>|cu VCSUpdate
|<Leader>|cU VCSUnlock
|<Leader>|cv VCSVimDiff
Vim, (\ cN, ) ,