garray: initialize allocated size in g_byte_array_new_take()

Internal allocation size (array->alloc) was being kept to 0 when a new
GByteArray was created from an already existing heap-allocated buffer.

Among other things, this was making g_byte_array_set_size() fully clear all
the buffer contents (not just the newly allocated memory) when
G_DEBUG=gc-friendly was being used...

  if (G_UNLIKELY (g_mem_gc_friendly))
    memset (array->data + array->alloc, 0, want_alloc - array->alloc);

https://bugzilla.gnome.org/show_bug.cgi?id=738170
Fix g_cond_timed_wait() timeout with !CLOCK_MONOTONIC

g_get_monotonic_time() and g_get_real_time() now always use different
clocks, so we cannot avoid correcting for their offset.  Fixes failure
to time out on Mac OS X.

https://bugzilla.gnome.org/show_bug.cgi?id=738197
Clarify g_propagate_error docs

I just ran into a bug that was caused by having src being a
persistent GError* that was not cleared after propagating it.
Updated Bulgarian translation
Add simple instance count facility

Add GOBJECT_DEBUG=instance-count which enables internal accounting
of the number of instances of each GType, and g_type_get_instance_count()
to retrieve the result.

https://bugzilla.gnome.org/show_bug.cgi?id=354457
Fix a return_if_fail confusion

This slipped through my editing of the patch.
signal: Keep only one list of emissions

There is no need to keep 2 lists.

This simplifies the code and gets rid of the only user inside glib of
G_HAVE_GROWING_STACK.

https://bugzilla.gnome.org/show_bug.cgi?id=736284
Bump version to 2.43.0

We have new API.
gfile: Clarify docs

Clarify corner cases that were unclear while reviewing a GTK patch.