t0014: test shadowing of aliases for a sample of builtins

t0014: test shadowing of aliases for a sample of builtins

The previous commit added tests for shadowing deprecated builtins.
Let’s make the test suite more complete by exercising a sample of
the builtins and in turn test the documentation for git-config(1):

    To avoid confusion and troubles with script usage, aliases that hide
    existing Git commands are ignored except for deprecated commands.

Signed-off-by: Kristoffer Haugsbakk <code@khaugsbakk.name>
Signed-off-by: Junio C Hamano <gitster@pobox.com>