The function is currently only being used for checking the result of
`git rev-parse --is-inside-work-tree`. Checking for the return code of
the command is enough.
as they were only being used by gitster prompt theme and kept for
Oh-My-Zsh compatibility. The newly introduced git-info module (inspired
by the git-info Prezto function) provides a more powerful
implementation than the Oh-My-Zsh inspired git_prompt_info.
Updated gitster to use the git-info module.
Closes#124
* remove unneeded explination and authorship comments (as it's
noted in the README.md)
* s/git/command git/ (see issue #30)
* add is-true function, as it is required by a few other functions.
