Squashed 'deps/libgit2/' changes from 4f9d541..89e9c16

89e9c16 Merge pull request #2318 from linquize/sleep
644592b Merge pull request #2320 from libgit2/rb/fix-starstar-again
d19b2f9 Make ** pattern eat trailing slash
d0420fc Make examples/status.c compile on Windows
9d878fc Merge pull request #2304 from jacquesg/solaris
183aa4f Check for NULL before passing it to vsnprintf
6b05240 strcasecmp is in <strings.h>
98b8fcf Build regex.c for Solaris. Added required defines for Solaris
c522bed Merge pull request #2314 from libgit2/cmn/known-libs
739040e Merge pull request #2315 from jacquesg/qsort-cygwin
90a4340 cygwin also doesn't have qsort_r
039e354 ciscript: don't use an empty string as a number
891b027 refs: document _next_name()
f5fc63b Don't exclude libssh2 from MinGW
096ac79 Workaround missing .pc files on FreeBSD
04739e9 Unquiet CMake output
892778e Merge pull request #2309 from jacquesg/midnightbsd
36a6151 MidnightBSD may also not have strnlen
041336e Merge pull request #2306 from odcinek/development_cmake
7f0de93 Make the build CMake 2.6 compatible
ec77105 Merge pull request #2301 from libgit2/cmn/pack-objects-memory
38d338b pack-objects: always write out the status in write_one()
c7f86ef zstream: grow based on used memory rather than allocated

git-subtree-dir: deps/libgit2
git-subtree-split: 89e9c1674c3a32758e31c400609b6f4351bbde4c
Update to libgit2 '89e9c1674c3a32758e31c400609b6f4351bbde4c'
20-pathspec.t: Update test case due to pattern matching rule changes in libgit2
Changes: update
Changes: update