Automated Build Generator

Disabled git password prompts in src/analysis/git.lisp

A new --non-interactive commandline option selects one of two behaviors:

1. When --non-interactive is supplied, the global option

-c core.askpass=true

is added to disable all username and password prompts (including
   keyrings via credentials helper).

2. When --non-interactive is not supplied, the environment variable

SSH_ASKPASS=true

is set for the git sub-process to disable default username and
   password prompts using the generator's terminal without affecting
   explicitly configured (via GIT_ASKPASS or core.askpass) credentials
   helper.

refs #1681

• src/analysis/util.lisp (header): updated copyright
  (run): accept environment keyword parameter, pass to
  `inferior-shell:run/nil'
• src/analysis/git.lisp (ssh-askpass-variable-name): new constant;
  SSH_ASKPASS environment variable
  (environment-with-ssh-askpass-overwritten): new function; helper for
  constructing environment with suitable SSH_ASKPASS value
  (%run-git): depending on new non-interactive keyword parameter, either
  call git executable with -c core.askpass=true global
  option or set SSH_ASKPASS=true in the environment of the sub-process
  (analyze uri eql :git): accept non-interactive keyword parameter, pass
  to `%run-git'
• src/commandline-interface/main.lisp (analyze-project): accept
  non-interactive keyword parameter, pass through
  (analyze-projects): similar
  (update-synopsis): added non-interactive commandline option
  (main): process non-interactive commandline option