before: gotadmin: lockfile timeout after: gotadmin: gc.pid.lock: lockfile timeout

This adds the functions got_repo_cleanup_prepare() and _complete() to lock/unlock the repository to prevent multiple `gotadmin cleanup' or `git gc' operations to run in parallel. improvements and ok stsp@

Rather than assume all dependencies are required for all programs, split them out. This will make packaging easier, as well as splitting the code to use subprojects. Note that due to the use of config.h semantics, in most cases the got_compat.h header file is now at the top of the .c file it is included in, so that it can handle the system header inclusion properly.

Now that the handling of including sys/queue.h is better, there's no need to remove those lines from the source. Copy the location of those original sys/queue.h lines from upstream at the same line number, so as to avoid any conflicts in the future.

suggested by millert ok thomas_adam

suggested by millert ok thomas_adam

This commit modifies the GoT main branch to be able to compile it under linux.

ok millert, naddy

also add got_error_prefix_errno2 and got_error_prefix_errno3 which should hopefully all be merged into a single function with variadic args (but can't alloc mem)