Merge branch 'ps/config-wo-the-repository'

Merge branch 'ps/config-wo-the-repository'

The config API had a set of convenience wrapper functions that
implicitly use the_repository instance; they have been removed and
inlined at the calling sites.

* ps/config-wo-the-repository: (21 commits)
  config: fix sign comparison warnings
  config: move Git config parsing into "environment.c"
  config: remove unused `the_repository` wrappers
  config: drop `git_config_set_multivar()` wrapper
  config: drop `git_config_get_multivar_gently()` wrapper
  config: drop `git_config_set_multivar_in_file_gently()` wrapper
  config: drop `git_config_set_in_file_gently()` wrapper
  config: drop `git_config_set()` wrapper
  config: drop `git_config_set_gently()` wrapper
  config: drop `git_config_set_in_file()` wrapper
  config: drop `git_config_get_bool()` wrapper
  config: drop `git_config_get_ulong()` wrapper
  config: drop `git_config_get_int()` wrapper
  config: drop `git_config_get_string()` wrapper
  config: drop `git_config_get_string()` wrapper
  config: drop `git_config_get_string_multi()` wrapper
  config: drop `git_config_get_value()` wrapper
  config: drop `git_config_get_value()` wrapper
  config: drop `git_config_get()` wrapper
  config: drop `git_config_clear()` wrapper
  ...