4.15 Fri Mar  1 12:04:50 CET 2013
- destroying a non-default loop would stop the global waitpid
  watcher (Denis Bilenko).
- queueing pending watchers of higher priority from a watcher now invokes
  them in a timely fashion (reported by Denis Bilenko).
- add throw() to all libev functions that cannot throw exceptions, for
  further code size decrease when compiling for C++.
- add throw () to callbacks that must not throw exceptions (allocator,
  syserr, loop acquire/release, periodic reschedule cbs).
- fix event_base_loop return code, add event_get_callback, event_base_new,
  event_base_get_method calls to improve libevent 1.x emulation and add
  some libevent 2.x functionality (based on a patch by Jeff Davey).
- add more memory fences to fix a bug reported by Jeff Davey. Better
  be overfenced than underprotected.
- ev_run now returns a boolean status (true meaning watchers are
  still active).
- ev_once: undef EV_ERROR in ev_kqueue.c, to avoid clashing with
  libev's EV_ERROR (reported by 191919).
- (ecb) add memory fence support for xlC (Darin McBride).
- (ecb) add memory fence support for gcc-mips (Anton Kirilov).
- (ecb) add memory fence support for gcc-alpha (Christian Weisgerber).
- work around some kernels losing file descriptors by leaking
  the kqueue descriptor in the child.
- work around linux inotify not reporting IN_ATTRIB changes for directories
  in many cases.
- include sys/syscall.h instead of plain syscall.h.
- check for io watcher loops in ev_verify, check for the most
  common reported usage bug in ev_io_start.
- chose socket vs. WSASocket at compiletime using EV_USE_WSASOCKET.
- always use WSASend/WSARecv directly on windows, hoping that this
  works in all cases (unlike read/write/send/recv...).
- try to detect signals around a fork faster (test program by
  Denis Bilenko).
- work around recent glibc versions that leak memory in realloc.
- rename ev::embed::set to ev::embed::set_embed to avoid clashing
  the watcher base set (loop) method.
- rewrite the async/signal pipe logic to always keep a valid fd, which
  simplifies (and hopefuly correctifies :) the race checking
  on fork, at the cost of one extra fd.
- add fat, msdos, jffs2, ramfs, ntfs and btrfs to the list of
  inotify-supporting filesystems.
- move orig_CFLAGS assignment to after AC_INIT, as newer autoconf
  versions ignore it before
  (https://bugzilla.redhat.com/show_bug.cgi?id=908096).
- add some untested android support.
- enum expressions must be of type int (reported by Juan Pablo L).

4.11 Sat Feb  4 19:52:39 CET 2012
- INCOMPATIBLE CHANGE: ev_timer_again now clears the pending status, as
  was documented already, but not implemented in the repeating case.
- new compiletime symbols: EV_NO_SMP and EV_NO_THREADS.
- fix a race where the workaround against the epoll fork bugs
  caused signals to not be handled anymore.
- correct backend_fudge for most backends, and implement a windows
  specific workaround to avoid looping because we call both
  select and Sleep, both with different time resolutions.
- document range and guarantees of ev_sleep.
- document reasonable ranges for periodics interval and offset.
- rename backend_fudge to backend_mintime to avoid future confusion :)
- change the default periodic reschedule function to hopefully be more
  exact and correct even in corner cases or in the far future.
- do not rely on -lm anymore: use it when available but use our
  own floor () if it is missing. This should make it easier to embed,
  as no external libraries are required.
- strategically import macros from libecb and mark rarely-used functions
  as cache-cold (saving almost 2k code size on typical amd64 setups).
- add Symbols.ev and Symbols.event files, that were missing.
- fix backend_mintime value for epoll (was 1/1024, is 1/1000 now).
- fix #3 "be smart about timeouts" to not "deadlock" when
  timeout == now, also improve the section overall.
- avoid "AVOIDING FINISHING BEFORE RETURNING" idiom.
- support new EV_API_STATIC mode to make all libev symbols
  static.
- supply default CFLAGS of -g -O3 with gcc when original CFLAGS
  were empty.

(fhajny)