This reduces memory and disk space consumption during packing. with tweaks + memleak on error fix from op@ ok op@

extend the support for git-style diffs to include the "pure rename" case, i.e. when a file is renamed without any edits. ok stsp@

Saves us from doing a malloc/free call for every item on the list. ok op@

tweak + ok tb@

This adds libbsd to the README files to indicate a core dependency. Originally from Ashish SHUKLA.

Bump the version in git now to the next version. Over time, this should really use the SHA1 to indicate a non-released build.

add a flag to got_patch to reverse a patch before applying and the -R flag for `got patch'. ok stsp@

as a cheap optimization got-read-patch was sending only the "\ No newline at end of file" lines that follows an addition (a "+" line). To be able to reverse patches in the future got_patch needs to know about all of these lines instead. No functional changes intended. ok stsp@

reminded by and 'looks fine' to stsp@

this allow to apply patches from subdirectories of the work tree root. Prodded by naddy@, ok stsp@.

The SHA implementation is found portably across systems, so don't include sha1.h directly.

This needs to be explicitly installed.

Now that siphash is being looked for in a portable way, don't assume <siphash.h> as this is most likely not going to be the case on non-BSD systems.

Siphash is being used in place of murmurhash for object-id set as this is faster. However, this isn't really seen much in the non-BSD userspace, so provide an implementation for it portably, if one isn't found.