Merge branch 'bc/more-git-var'

Add more "git var" for toolsmiths to learn various locations Git is configured with either via the configuration or hardcoded defaults. * bc/more-git-var: var: add config file locations var: add attributes files locations attr: expose and rename accessor functions var: adjust memory allocation for strings var: format variable structure with C99 initializers var: add support for listing the shell t: add a function to check executable bit var: mark unused parameters in git_var callbacks