baseparse: Fix splitting and reversing of GOPs in reverse playback mode

We iterate the current discont group backwards and push each GOP forwards,
starting from the last one. However if the first buffer in the current
discont group is a keyframe, we will keep it around until next time,
which is far from ideal. Just push it.
pad: Include event type in debug output when delaying a sticky event because of not-linked
scripts: gst-uninstalled: gst-plugins-gl libs got merged into -bad
gst-inspect: Add missing \n in output
gst-launch.1: Playbin2 is dead, long live playbin

Looks like that was the last remaining mention in core ...
basesrc: removing duplicated inner if

The inner if replicates the same code of the outer and is useless
as flag_segment will always be true.

Found by coverity.
baseparse: Make sure to set the DISCONT flag on the first buffer of each GOP in reverse playback mode
inputselector: fix build with debug cached buffers enabled

gstinputselector.c:818:5: error: format not a string literal
and no format arguments [-Werror=format-security]
gstvalue: Fix comparison of int/int64 range

Checking step three times seems unnecessary.
A similar bug was fixed for double range in
commit 3ea6b04c10b10fde9d62190068f274b940edef07
gstvalue: Prevent division or modulo by zero

The step can end up being zero if the underlying value isn't a valid
range GValue.

In those cases, return FALSE.

We don't use g_return*_if_fail since it will already have been triggered
by the above-mentionned _get_step() functions.

Spotted by Coverity.
adapter: Remove always-true-checks

a gsize is guaranteed to be positive on all systems since it's an
unsigned value.

CID #1037145
CID #1037146
baseparse: Remove always-true-checks

a gsize is guaranteed to be positive on all systems since it's an
unsigned value.

CID #1037147
debugutils: Handle caps field values being NULL

GST_DEBUG_BIN_TO_DOT_FILE() would cause a segfault whenever it encountered an
element's caps that had a field value being NULL. Such fields are successfully
handled e.g. by GST_*_OBJECT(), and with this patch so does
GST_DEBUG_BIN_TO_DOT_FILE(). Even if string fields with a NULL value are
not supposed to be valid in caps, such caps can be created.

Fixes https://bugzilla.gnome.org/show_bug.cgi?id=727701
parse: Don't dist the bison and flex generated headers

https://bugzilla.gnome.org/show_bug.cgi?id=727253
filesrc: catch failure to seek back to zero after seek test

This should never happen theoretically, but since a transient
failure would get us to silently read wrong data, it's worth
erroring out. And it silence this:

Coverity 206034
filesrc: no need for a translated message for impossible error cases

The message is too technical anyway, the default message works
just fine here as well.
check: only call setpgid on valid child PIDs

Coverity 206186
queue2: warn if we can't remove our temporary file

It's not fatal though, so do not error out.

Coverity 1037121
Revert "check: only call setpgid on valid child PIDs"

This reverts commit b9313afc75b68d986e473b76b55543456857912b.

This should be fixed in upstream libcheck instead. We want
to keep diff of our local copy to upstream libcheck
to a minimum.
queue2: use g_strerror() instead of strerror()

Need UTF-8 encoding.